Tire size comparisons
One page per pairing worth asking about, and a tool for every other pairing there is.
There is a page here only where a real question keeps recurring. Almost all of them take one of two shapes: the size a platform left the factory with against the size its owners commonly step up to, or a metric size against the imperial size people assume it is equivalent to.
That second shape is where most of the surprise lives. Sizes sold as 33s span most of an inch. Sizes sold as 35s span more. The arithmetic is the only way to know which of two tires marketed as the same thing is actually taller, and by how much.
Why there is no page for every pairing
Because the combinatorics are absurd and the pages would be worthless. With a catalogue of this size, every possible pairing runs to five figures, and each page would say the same thing with two numbers changed. That is the pattern search engines demote and readers never see.
Instead: a curated set here, and a tool that answers any pairing at all. The tool takes both sizes in the address bar, so a result you calculate is a link you can send.
What each page shows
The drawing first, to scale, both tires on the same ground line with width bars underneath. Then the full table: overall diameter, section width, sidewall height, circumference, revolutions per mile, the change in ride height at the axle, and the speedometer error the swap causes. Then the prose about that specific pairing — what makes it worth asking about, and what the numbers do not cover.
One page per pairing, not one per truck
A pairing asked about on five different platforms is one page here, and that page names all five. It is not five pages that differ only in which truck is mentioned in the first sentence.
That decision removed more than a dozen near-identical pages before any of them was written, and it makes the surviving pages better: the arithmetic of 265/70R17 against 285/70R17 is the same on a Tacoma, an F-150 and a Frontier, and a reader who owns one of the three is not helped by three copies of it.
The two shapes, in more detail
Platform pairings start from a size a vehicle genuinely left the factory with. They are the ones where the second number is a decision rather than a curiosity, and where gearing sometimes enters the conversation.
Equivalence and isolation pairings are asked on their own account. Some are the metric-versus- imperial question in its various forms. Others deliberately hold one variable still — the same width at two aspect ratios, or the same height at two widths — because that is the cleanest way to see what a single dimension actually does. Those are the most useful pages here for anybody trying to build an intuition rather than answer one question.
What no page here decides
Whether either size fits. Every comparison ends at the arithmetic, because clearance and load rating are properties of a vehicle and a wheel rather than of a size code. The pages will tell you that one tire is 1.28 in wider than the other; whether that 1.28 in finds your inner fender is a question for a tape measure.
Asked about a specific platform
Pairings where the question is nearly always about one vehicle, so the page names it.
- 245/75R17 vs 35x12.50R17245/75R17 vs 35x12.50R17 — two rungs in one moveA Wrangler JL Sport's 31.47 in factory tire against a 35.00 in flotation size: 3.53 in taller, 2.85 in wider, and 11.22% of speedometer error.
- 255/75R17 vs 33x12.50R17255/75R17 vs 33x12.50R17 — under an inch of height, two and a half of width32.06 in to 33.00 in is 0.94 in and 2.94%. Section width goes from 10.04 in to 12.50 in, which is 24.51% more casing.
- 255/75R17 vs 35x12.50R17255/75R17 vs 35x12.50R17 — where speedometer error matters32.06 in to 35.00 in is 2.94 in and 9.17%. The dial reads 70 while the vehicle does 76.4, and every hundred recorded miles are 109.2 covered.
- 285/70R17 vs 37x12.50R17285/70R17 vs 37x12.50R17 — from the factory 33 to a real 3732.71 in to 37.00 in is 4.29 in and 13.12%. A Rubicon's 4.10 axles would need 4.64:1 to hold the same engine speed, and 4.64 is not a ratio anyone sells.
- 285/70R17 vs 35x12.50R17285/70R17 vs 35x12.50R17 — the step a Rubicon usually takes32.71 in to 35.00 in, 2.29 in and 7.01%, with the sidewall growing 1.15 in to a full 9.00 in on an unchanged 17-inch wheel.
- 255/75R17 vs 285/70R17255/75R17 vs 285/70R17 — two factory Wrangler sizes32.06 in against 32.71 in. Only 0.65 in of height separates them, but the wider size carries 1.18 in more casing — nearly twice the height difference.
- 225/75R16 vs 31x10.50R15225/75R16 vs 31x10.50R15 — a generation apart, not a swapA Wrangler JK's smallest factory size at 29.29 in against the 31.00 in flotation tire its predecessor wore. Different wheels, 1.71 in of height, 1.64 in of width.
- 215/75R15 vs 31x10.50R15215/75R15 vs 31x10.50R15 — the step almost every TJ takes27.70 in to 31.00 in: 3.30 in of diameter, 11.93% of speedometer error, and a sidewall that grows from 6.35 in to a full 8.00 in.
- 215/75R15 vs 33x12.50R15215/75R15 vs 33x12.50R15 — the biggest step on this site27.70 in to 33.00 in is 19.15%, the largest proportional jump in the whole comparison set. An indicated 70 mph becomes an actual 83.4 mph.
- 245/75R17 vs 33x12.50R17245/75R17 vs 33x12.50R17 — a Gladiator's first upgrade31.47 in to 33.00 in: 1.53 in taller and 2.85 in wider, which is 29.59% more casing for 4.87% more height.
- 265/70R16 vs 285/75R16265/70R16 vs 285/75R16 — 33 inches without leaving 16s30.61 in to 32.83 in on the same 16-inch wheel. 2.22 in, 7.27%, and the closest a widely-stocked metric size gets to a real 33 on a wheel this small.
- 265/70R16 vs 265/75R16265/70R16 vs 265/75R16 — one profile step on a 16-inch wheelThe same 10.43 in casing, five points apart: 30.61 in becomes 31.65 in, a change of 1.04 in with no width change at all.
- 265/65R17 vs 285/70R17265/65R17 vs 285/70R17 — two variables moving at once20 mm of extra width and five points of extra aspect ratio compound into 2.15 in of diameter, 7.02%, and 43 fewer wheel revolutions per mile.
- 265/70R17 vs 285/70R17265/70R17 vs 285/70R17 — the commonest step in the catalogue31.61 in to 32.71 in. Twenty millimetres of width at a fixed 70-series profile, worth 1.10 in of diameter and 3.49% of speedometer reading.
- 265/65R17 vs 33x10.50R17265/65R17 vs 33x10.50R17 — height without width30.56 in to 33.00 in — 2.44 in taller — while the section width moves 0.07 in, from 10.43 in to 10.50 in.
- 265/60R18 vs 275/70R17265/60R18 vs 275/70R17 — the smaller wheel, the taller tire30.52 in to 32.16 in. Dropping a wheel size while adding ten points of aspect ratio produces 1.64 in more diameter and 1.32 in more sidewall.
- 245/75R17 vs 285/70R17245/75R17 vs 285/70R17 — base trim to off-road trim31.47 in to 32.71 in, a 1.24 in step, with the section width jumping 1.57 in from 9.65 in to 11.22 in. The width is the bigger change.
- 265/70R17 vs 275/70R17265/70R17 vs 275/70R17 — is 10 mm worth doing?One width increment on the same wheel at the same aspect ratio: 0.39 in wider, 0.55 in taller, 1.74%. The height change is a by-product of the width change.
- 265/70R17 vs 33x12.50R17265/70R17 vs 33x12.50R17 — factory tire, an advertised 3331.61 in to 33.00 in is 1.39 in and 4.41%, and the casing grows 2.07 in — nearly 20% wider — from 10.43 in to 12.50 in.
- 245/60R20 vs 265/70R17245/60R20 vs 265/70R17 — three inches of wheel, same height31.57 in against 31.61 in. A 4Runner's 20-inch Limited wheels and its 17-inch off-road wheels roll within four hundredths of an inch of each other.
- 275/65R18 vs 285/75R18275/65R18 vs 285/75R18 — a 35 without changing wheels32.07 in to 34.83 in, 2.76 in and 8.59%, with the sidewall growing from 7.04 in to 8.42 in on the same 18-inch wheel.
- 265/60R20 vs 35x12.50R20265/60R20 vs 35x12.50R20 — the biggest thing on a factory 2032.52 in to 35.00 in: 2.48 in and 7.63%, with the casing widening 2.07 in from 10.43 in to 12.50 in.
- 275/65R18 vs 285/65R18275/65R18 vs 285/65R18 — the step you take to change nothing32.07 in to 32.59 in: 0.51 in, 1.60%, and 0.39 in of extra casing. The smallest meaningful move available on an 18-inch F-150.
- 275/55R20 vs 33x12.50R20275/55R20 vs 33x12.50R20 — what a 33 is on a 20-inch wheelA truck calibrated for a 31.91 in tire against a real 33.00 in one: 1.09 in taller, 1.67 in wider, 3.42%. The flotation size has only 6.50 in of sidewall.
- 275/60R20 vs 35x12.50R20275/60R20 vs 35x12.50R20 — two inches on a half-ton32.99 in to 35.00 in: 2.01 in taller, 1.67 in wider, 6.09% of speedometer error, and an axle ratio arithmetic that starts asking questions.
- 275/65R18 vs 285/65R20275/65R18 vs 285/65R20 — two inches of wheel and half an inch of tire32.07 in to 34.59 in, a gain of 2.51 in, of which the wheel provides two inches and the tire the remaining half.
- 315/70R17 vs 37x12.50R17315/70R17 vs 37x12.50R17 — largest metric size, factory 3734.36 in to 37.00 in, a gain of 2.64 in and 7.68%, with the section width almost unchanged at 12.40 in against 12.50 in.
- 255/70R16 vs 33x12.50R15255/70R16 vs 33x12.50R15 — only works as arithmeticA modern 30.06 in metric size against a 33.00 in flotation tire on a smaller wheel. 2.94 in of height, 2.46 in of width, and two incompatible wheel diameters.
- 255/70R16 vs 265/70R17255/70R16 vs 265/70R17 — the wheel eats most of the sidewall30.06 in to 31.61 in. An inch of extra wheel and 10 mm of extra width net out at 1.55 in of diameter, not the 1.00 in the wheel alone would suggest.
- 275/70R18 vs 37x12.50R20275/70R18 vs 37x12.50R20 — the largest common Super Duty fitment33.16 in to 37.00 in is 3.84 in and 11.59%. Two inches of that is wheel, and the sidewall still grows 0.92 in to 8.50 in.
- 275/65R18 vs 35x12.50R20275/65R18 vs 35x12.50R20 — load range ahead of diameter32.07 in to 35.00 in, 2.93 in and 9.12%. Two inches of extra wheel, 1.67 in of extra casing, and half an inch of extra sidewall.
- 275/60R20 vs 33x12.50R20275/60R20 vs 33x12.50R20 — the same tire in two notations32.99 in against 33.00 in, with identical 6.50 in sidewalls. The height difference is one hundredth of an inch; the width difference is 1.67 in.
- 265/65R18 vs 275/70R18265/65R18 vs 275/70R18 — height without much extra casing31.56 in to 33.16 in, an increase of 1.59 in and 5.05%, from just 0.39 in of extra section width.
- 255/70R17 vs 285/70R17255/70R17 vs 285/70R17 — 30 mm on the Silverado's smaller wheel31.06 in to 32.71 in, a 1.65 in step from 1.18 in of extra casing width at an unchanged 70-series profile.
- 275/55R20 vs 285/65R20275/55R20 vs 285/65R20 — the metric route to a 34-inch tire31.91 in to 34.59 in is 2.68 in and 8.39%, from 10 mm of width and ten points of aspect ratio, on the same 20-inch wheel.
- 265/65R17 vs 265/70R17265/65R17 vs 265/70R17 — sidewall on its ownIdentical 10.43 in casings, five points of aspect ratio apart. The tire grows 1.04 in in diameter and not one thousandth of an inch in width.
- 265/60R18 vs 285/70R17265/60R18 vs 285/70R17 — dropping a wheel size to gain two inches of tire30.52 in to 32.71 in, a gain of 2.19 in and 7.17%, achieved while the wheel gets an inch smaller and the sidewall grows 1.59 in.
- 275/60R20 vs 285/65R20275/60R20 vs 285/65R20 — the AT4 step, casing over size32.99 in to 34.59 in, 1.59 in and 4.83%, from 10 mm of width and five points of profile on an unchanged 20-inch wheel.
- 285/45R22 vs 275/50R22285/45R22 vs 275/50R22 — the narrower tire is the taller one32.10 in against 32.83 in. Dropping 10 mm of width and gaining five points of profile makes the tire 0.73 in taller, not shorter.
- 265/70R17 vs 33x12.50R20265/70R17 vs 33x12.50R20 — a wheel and a tire, priced as one31.61 in to 33.00 in with the wheel growing three inches at the same time. The sidewall does not grow; it shrinks, from 7.30 in to 6.50 in.
- 275/70R18 vs 35x12.50R20275/70R18 vs 35x12.50R20 — a Ram 2500's usual upgrade33.16 in to 35.00 in, 1.84 in and 5.56%. The wheel gains two inches while the sidewall loses 0.08 in, so the tire gets taller and less compliant at once.
- 265/75R16 vs 33x12.50R16265/75R16 vs 33x12.50R16 — the Frontier's tall option against a real 3331.65 in to 33.00 in, a difference of 1.35 in. The flotation size is 2.07 in wider and carries 0.68 in more sidewall.
- 225/65R17 vs 235/65R17225/65R17 vs 235/65R17 — smaller than a set of tires wears28.52 in to 29.03 in, a difference of 0.51 in and 1.79%. That is roughly the diameter a tire loses over its own service life.
- 225/65R17 vs 245/65R17225/65R17 vs 245/65R17 — 20 mm that buys an inch of heightHolding the aspect ratio at 65 and adding 20 mm of width takes the tire from 28.52 in to 29.54 in. The extra inch of diameter is a side effect of the extra width, not a separate decision.
- 225/60R17 vs 235/60R17225/60R17 vs 235/60R17 — the smallest step the system offersOne 10 mm width increment at a fixed aspect ratio: 0.39 in wider, 0.47 in taller, 1.71%. Nothing else about the fitment changes.
- 225/60R17 vs 245/65R17225/60R17 vs 245/65R17 — a truck-sized step on a car-based platform27.63 in to 29.54 in is 1.91 in and 6.91%. Twenty millimetres of width and five points of aspect ratio compound into nearly two inches of diameter.
- 235/65R17 vs 245/65R17235/65R17 vs 245/65R17 — where the extra half inch of height comes from29.03 in to 29.54 in. Ten millimetres of width adds 0.26 in of sidewall automatically, and the sidewall counts twice.
- 255/70R18 vs 265/70R18255/70R18 vs 265/70R18 — small enough for air suspension32.06 in to 32.61 in, 0.55 in and 1.72%. Ten millimetres of width, 0.39 in of casing, and a quarter inch at the axle.
- 255/65R19 vs 255/70R18255/65R19 vs 255/70R18 — the same tire on two wheel sizes32.05 in against 32.06 in, identical section width, and a rolling-diameter difference of 0.00 in to two decimal places. The only thing that changes is 0.50 in of sidewall.
- 285/60R18 vs 285/65R18285/60R18 vs 285/65R18 — five points on the widest common casing31.46 in to 32.59 in with the width fixed at 11.22 in. A single aspect step is worth 1.12 in here — more than the same step on any narrower tire.
- 245/70R17 vs 265/70R17245/70R17 vs 265/70R17 — 20 mm on the same wheel30.50 in to 31.61 in: 1.10 in of extra diameter from 0.79 in of extra width, at an unchanged 70-series aspect ratio.
- 265/50R20 vs 275/55R20265/50R20 vs 275/55R20 — a taller sidewall does the work30.43 in to 31.91 in. Five points of profile and 10 mm of width combine into 1.48 in of diameter and 4.85% of speedometer error.
- 225/75R15 vs 31x10.50R15225/75R15 vs 31x10.50R15 — the size that defined a platformAn XJ Cherokee's stock 28.29 in tire against the 31.00 in flotation size the platform is remembered for. 2.71 in taller, 1.64 in wider, 9.59% on the speedometer.
- 235/75R15 vs 33x12.50R15235/75R15 vs 33x12.50R15 — four inches on a 15-inch wheel28.88 in to 33.00 in is 4.12 in and 14.27%, with the section width rising from 9.25 in to 12.50 in — a third again as wide.
- 235/55R17 vs 235/50R18235/55R17 vs 235/50R18 — width held constant on purposeThe same 235 mm casing on two wheels. Only the aspect ratio moves, the diameter changes 0.07 in, and the section width is identical at 9.25 in.
- 255/40R19 vs 275/35R19255/40R19 vs 275/35R19 — more width, less tire27.03 in down to 26.58 in. Adding 20 mm of section width while dropping five points of profile makes the tire 0.45 in shorter, not taller.
- 215/55R16 vs 225/45R17215/55R16 vs 225/45R17 — the plus-one that goes backwardsThe bigger wheel carries the smaller tire here: 25.31 in drops to 24.97 in, a loss of 0.34 in and 1.34% of speedometer reading.
- 215/55R17 vs 235/45R18215/55R17 vs 235/45R18 — a factory plus-one, to two decimals26.31 in against 26.33 in. Twenty millimetres of width, ten points of aspect ratio and one inch of wheel, and the rolling diameter moves 0.02 in.
- 205/55R16 vs 225/40R18205/55R16 vs 225/40R18 — a plus-two that drifts upwardTwo wheel sizes for 0.90 in of sidewall. The 18-inch fitment ends up 0.21 in taller than the 16, which is 0.84% and the wrong direction for a swap meant to change nothing.
- 195/65R15 vs 225/45R17195/65R15 vs 225/45R17 — three wheel sizes, one hundredth of an inch24.98 in against 24.97 in. Two inches of extra wheel and 30 mm of extra width, and the rolling diameter does not move at all.
Asked on their own
Equivalence questions and isolation cases — one variable moving at a time.
- 285/70R17 vs 33x12.50R17285/70R17 vs 33x12.50R17 — is the metric size really a 33?285/70R17 is 32.71 in tall; 33x12.50R17 is 33.00 in. The height gap is 0.29 in and the width gap is 1.28 in, which is the part people do not expect.
- 315/70R17 vs 35x12.50R17315/70R17 vs 35x12.50R17 — both sold as 35s, and one is not34.36 in against 35.00 in. The widths are within 0.10 in of each other, so the whole difference between these two "35s" is 0.64 in of height.
- 305/70R17 vs 35x11.50R17305/70R17 vs 35x11.50R17 — the narrow-35 question33.81 in against 35.00 in. The metric size is 1.19 in shorter than the imperial one and 0.51 in wider, so neither is bigger in both dimensions.
- 295/70R17 vs 34x10.50R17295/70R17 vs 34x10.50R17 — the gap between a 33 and a 3533.26 in against 34.00 in. Two uncommon sizes that occupy the same niche from opposite directions — one wide and shorter, one narrow and taller.
- 265/70R17 vs 32x11.50R17265/70R17 vs 32x11.50R17 — equivalence at the small end31.61 in against 32.00 in. The metric size is 0.39 in short of a nominal 32, and 1.07 in narrower than the flotation tire that names itself one.
- 275/70R18 vs 33x12.50R18275/70R18 vs 33x12.50R18 — the metric size is the taller one33.16 in against 33.00 in. The size with no 33 in its name is 0.16 in taller than the one that has it, and carries a marginally taller sidewall too.
- 285/75R16 vs 33x12.50R16285/75R16 vs 33x12.50R16 — the closest metric-imperial match32.83 in against 33.00 in, and sidewalls of 8.42 in against 8.50 in. Two-thirds of an inch of the difference is width; the height gap is 0.17 in.
- 35x12.50R20 vs 285/65R2035x12.50R20 vs 285/65R20 — how much of a 35 survives on a 2035.00 in against 34.59 in, with sidewalls of 7.50 in and 7.29 in. The metric size comes within 0.41 in of a real 35 — closer than most metric substitutes manage.
- 33x12.50R20 vs 275/65R2033x12.50R20 vs 275/65R20 — the metric size is the taller one33.00 in against 34.07 in. The tire without a number in its name stands 1.07 in higher, and does it on a casing 1.67 in narrower.
- 37x12.50R17 vs 315/70R1737x12.50R17 vs 315/70R17 — going down, and why the percentage changesStepping from a 37.00 in tire to a 34.36 in one is a 7.13% over-read, where the same swap in the other direction is 7.68%. Same two tires, different reference.
- 195/65R15 vs 205/55R16195/65R15 vs 205/55R16 — the plus-one everyone learns onAn inch of wheel bought with half an inch of sidewall. 195/65R15 stands 24.98 in, 205/55R16 stands 24.88 in, and the substitution lands a tenth of an inch low.
- 205/55R16 vs 225/45R17205/55R16 vs 225/45R17 — plus-sizing done properly24.88 in against 24.97 in. A whole inch of extra wheel changes the rolling diameter by 0.09 in, which is what a plus-one is supposed to achieve and frequently does not.
- 225/45R17 vs 235/40R18225/45R17 vs 235/40R18 — the sidewall runs out first24.97 in to 25.40 in. The wheel grows an inch, the sidewall can only find 0.29 in to give, and the diameter drifts up 1.72% as a result.
- 235/45R18 vs 245/40R19235/45R18 vs 245/40R19 — the same climb, one wheel higher26.33 in to 26.72 in. The aspect step releases 0.31 in of sidewall where half an inch was needed, so the diameter drifts up 1.48%.
- 245/40R18 vs 255/35R19245/40R18 vs 255/35R19 — the two changes nearly cancel25.72 in to 26.03 in. A 10 mm width increase and a five-point profile drop leave 0.31 in of drift, or 1.21%.
- 235/85R16 vs 285/75R16235/85R16 vs 285/75R16 — height and width are separate axes31.73 in against 32.83 in, but 9.25 in against 11.22 in. The taller tire is only 1.10 in taller and 1.97 in wider, which is the cleanest proof that the two dimensions move independently.
- 255/80R17 vs 285/70R17255/80R17 vs 285/70R17 — same height, 30 mm apart33.06 in against 32.71 in. The narrow 80-series size is the taller of the two by 0.35 in while being 1.18 in slimmer.
- 33x10.50R17 vs 33x12.50R1733x10.50R17 vs 33x12.50R17 — same height, two inches apartBoth are 33.00 in tall with 8.00 in sidewalls and 611.2 revolutions per mile. The only difference between them is 2.00 in of section width.
- 35x11.50R17 vs 35x12.50R1735x11.50R17 vs 35x12.50R17 — one inch of width, nothing elseBoth are 35.00 in tall with 9.00 in sidewalls and 576.2 revolutions per mile. The only difference is 1.00 in of section width.
- 245/75R16 vs 265/70R16245/75R16 vs 265/70R16 — two routes to the same 30-inch tire30.47 in against 30.61 in, a difference of 0.14 in. One reaches it with a tall sidewall on a narrow casing, the other with a shorter sidewall on a wider one.
- 265/70R17 vs 245/75R17265/70R17 vs 245/75R17 — narrower without getting shorter31.61 in against 31.47 in. Dropping 20 mm of section width and adding five points of aspect ratio costs 0.14 in of diameter, which is 0.44%.
- 275/55R20 vs 275/60R20275/55R20 vs 275/60R20 — one profile step, nothing elseSame 10.83 in casing, same 20-inch wheel, five points of aspect ratio: 31.91 in becomes 32.99 in, a change of 1.08 in.
- 31x10.50R15 vs 33x12.50R1531x10.50R15 vs 33x12.50R15 — the sizes that defined an eraTwo inches of diameter and two inches of width: 31.00 in to 33.00 in and 10.50 in to 12.50 in, for 6.45% of speedometer error.
- 37x12.50R17 vs 40x13.50R1737x12.50R17 vs 40x13.50R17 — the top of the flotation range37.00 in to 40.00 in and 12.50 in to 13.50 in. An 11.50 in sidewall, 504.2 revolutions per mile, and 8.11% of speedometer error.
- 30x9.50R15 vs 31x10.50R1530x9.50R15 vs 31x10.50R15 — the flotation ladder starts hereOne inch of diameter and one inch of width, exactly. 30.00 in to 31.00 in, 9.50 in to 10.50 in, and 3.33% of speedometer error.