What is total tire height and how is it calculated?

Total tire height — also called overall diameter — is the full outside-to-outside measurement of a mounted tire. It equals the wheel (rim) diameter plus twice the sidewall height. Sidewall height is derived from the P-metric code: Sidewall (in) = (Width mm × Aspect Ratio ÷ 100) ÷ 25.4. For a 265/70R17 tire: sidewall = (265 × 0.70) ÷ 25.4 = 7.30 in, giving a total height of 17 + 2 × 7.30 = 31.61 in.

What is the ±3% rule for tire height changes?

The ±3% rule states that a replacement tire's total height should stay within 3% of the OEM tire's total height to preserve speedometer accuracy and ABS/stability control calibration. For a stock 265/70R17 (31.61 in), the safe window is 30.66–32.56 in. Exceeding ±3% on a passenger car risks ABS fault codes, transmission shift-point errors, and inaccurate speedometer readings. On AWD and 4WD vehicles, manufacturers often tighten this tolerance to ±1% to protect the transfer case and rear differential.

Is tire height the same as tire diameter?

Yes — tire height and overall tire diameter are the same measurement: the outer diameter of the fully inflated, mounted tire from contact patch to top. Both terms describe the same dimension. 'Height' is the informal term most people use, especially for off-road and lifted-truck applications. 'Overall diameter' is the engineering term used in manufacturer documentation and ISO/SAE standards.

How do I calculate tire height in inches from a metric size?

Use this three-step process: (1) Sidewall height in mm = Width × (Aspect ÷ 100). (2) Convert to inches: divide by 25.4. (3) Total height = rim diameter + 2 × sidewall in inches. Example for 225/65R17: sidewall = 225 × 0.65 = 146.25 mm = 5.76 in. Total height = 17 + 2 × 5.76 = 28.52 in.

What metric tire size equals a 33-inch tire?

The most common 33-inch metric equivalents on a 17-inch rim are 285/75R16 (32.83 in) and 275/70R18 (33.16 in). On a 17-inch rim, 285/70R17 measures 32.71 in and 315/70R17 measures 34.36 in. On an 18-inch rim, 275/65R18 comes in at 32.07 in and 285/65R18 at 32.59 in. The Find by Height tab scans all combinations ±2% of 33 inches for any rim size you choose.

Does a taller tire improve ground clearance?

Yes — every 2 inches of additional total height raises ground clearance at the axle center by exactly 1 inch, since the axle sits at the tire's radius. A 33-inch tire gives 16.5 in of ground clearance (at the axle), while a 35-inch tire gives 17.5 in. This calculation only applies to the axle-level clearance — actual body/frame clearance also depends on suspension lift, wheel offset, and the physical space in the wheel well.

How does tire height affect speedometer reading?

A taller tire has a larger circumference and travels further per revolution, so the wheel makes fewer revolutions per mile. Speedometers count wheel revolutions and multiply by the expected circumference — if the circumference is larger than expected, the speedometer reads lower than your actual speed. Formula: True Speed = Indicated Speed × (New Height ÷ OEM Height). A tire 5% taller than OEM means your speedometer reads 50 mph when you are actually doing 52.5 mph.

What is the difference between sidewall height and total tire height?

Sidewall height is only the tire's rubber section — from the rim bead to the outer tread. Total height (overall diameter) is the complete measurement from ground to top, which equals the rim diameter plus two sidewall heights. For a 225/45R17: sidewall = (225 × 0.45) ÷ 25.4 = 3.99 in. Total height = 17 + 2 × 3.99 = 24.97 in. The aspect ratio in a P-metric code is the sidewall-height-to-width ratio, not the full height.

How do I find the correct tire size for a target total height?

Use the Find by Height tab: enter your target in inches and your rim size, and the calculator scans all standard metric widths (155–315 mm) and aspect ratios (30–80) to return every size within ±2% of your target. Results are sorted by closest match. This is the fastest way to find a metric equivalent for a floatation inch target (e.g., "I want a 35-inch tire on 18-inch rims").

Do wider tires have a different height than narrower tires with the same aspect ratio?

Yes — aspect ratio is a percentage of section width, so a wider tire with the same aspect ratio has a taller sidewall and a larger total height. For example, a 225/65R17 has a sidewall of (225 × 0.65) ÷ 25.4 = 5.76 in and a total height of 28.52 in. A 265/65R17 has a sidewall of (265 × 0.65) ÷ 25.4 = 6.78 in and a total height of 30.55 in — over 2 inches taller despite both using a 65-series aspect ratio and the same 17-inch rim.

Tire Height Calculator

A 265/70R17 tire has a total height of 31.61 inches (802.9 mm). Formula: rim diameter + 2 × sidewall height. Safe replacement window: ±3% for street vehicles, ±1% for AWD. Five calculation modes below.

Quick Answer

A Toyota Tacoma leaves the factory on 265/70R17 tires — total height of 31.61 inches (802.9 mm). A popular upgrade to 285/75R17 raises height to 33.83 inches (+6.8%) — beyond the passenger-car ±3% guideline but acceptable on this body-on-frame truck with a 2-inch leveling kit. Formula: Total Height = Rim Diameter + 2 × (Width mm × Aspect ÷ 100 ÷ 25.4).

Tire Size	Height (in)	Height (mm)	Typical Vehicle
205/55R16	24.88″	631.9 mm	Midsize sedan (Camry)
225/65R17	28.44″	722.4 mm	Crossover (RAV4, CR-V)
265/70R17	31.61″	802.9 mm	Truck (Tacoma stock)
275/65R18	32.07″	814.6 mm	Half-ton truck (F-150)
285/75R16	32.83″	834.0 mm	Jeep Wrangler / off-road
315/70R17	34.36″	872.7 mm	Lifted truck / heavy off-road

Street vehicles: stay within ±3% of OEM height. AWD vehicles (Subaru, Audi quattro): ±1–1.5%.

Metric · Inches · Compare · Find

InchesMetric

Tire Height Calculator — Metric Size (P-Metric)

Common sizes — quick load:

Tire Size (e.g. 225/65R17)

Pre-Computed Heights — 12 Popular Metric Sizes

Height (in)	Height (mm)	Sidewall (in)	Circumference (in)	Revs/Mile	Category
24.47″	621.5	4.73″	76.87″	824	Economy sedan
24.98″	634.5	4.99″	78.48″	807	Compact
24.88″	631.9	4.44″	78.16″	811	Midsize sedan
26.16″	664.4	5.08″	82.18″	771	Family car
24.97″	634.3	3.99″	78.45″	808	Sport sedan
28.52″	724.3	5.76″	89.58″	707	Crossover / SUV
28.18″	715.7	5.09″	88.52″	716	Mid-size SUV
26.68″	677.7	4.34″	83.82″	756	Performance
31.61″	802.8	7.30″	99.29″	638	Truck / light off-road
32.07″	814.7	7.04″	100.77″	629	Half-ton truck
32.83″	833.9	8.42″	103.14″	614	Jeep / off-road
34.36″	872.8	8.68″	107.95″	587	Lifted truck

Click any size to load it into the calculator above.

How to Use This Calculator

1Metric Size tab. Type your P-metric tire code (e.g. 225/65R17) or click a preset. Click "Calculate Height" to see total height, sidewall, circumference, and revs/mile in both inches and mm.
2Inches Direct tab. Enter the rim diameter and the tire sidewall height in inches. Use this for floatation sizes (35×12.5R17), trailer tires, or any tire where you have a physical measurement.
3Compare Two tab. Enter Size A (your current/OEM tire) and Size B (your proposed new tire). The calculator outputs height delta, safety badge (ideal/acceptable/caution/danger), a visual SVG comparison, and a per-speed speedometer correction table.
4Wheel + Tire Total tab. Enter wheel rim diameter and one sidewall height in inches to see the complete assembled height — useful for custom builds, trailers, and ground-clearance planning.
5Find by Height tab. Enter a target height in inches and a rim size. The calculator scans over 1,000 standard metric combinations and returns every size within ±2%, sorted by closest match.

Tire Height — Key Formulas and Rules

Sidewall height is a percentage of width. The aspect ratio in a P-metric code (the middle number, e.g. "65" in 225/65R17) is the sidewall-height-to-width ratio as a percentage. A 225/65R17 has a sidewall of 225 × 0.65 = 146.25 mm = 5.76 in. Wider tires with the same aspect ratio are proportionally taller.

Every +2 inches of tire height = +1 inch of axle clearance. Ground clearance at the axle center equals the tire radius (half the total height). Upgrading from a 33-inch to a 35-inch tire adds 1 inch of axle-level clearance — but only if no suspension changes are made. Body/frame clearance depends on lift height and wheel well dimensions.

The ±3% rule applies to passenger cars and crossovers. Street vehicles must stay within ±3% of OEM total height for ABS and speedometer calibration. AWD vehicles (Subaru, Audi quattro, Toyota 4WD) tighten to ±1–1.5% to protect the center differential. Body-on-frame trucks and Jeeps are more tolerant at ±10% before re-gearing becomes necessary.

Floatation inch sizes (35×12.5R17) work differently. The "35" in a floatation size is the approximate total height in inches, "12.5" is the approximate section width, and "17" is the rim diameter. These are nominal, not calculated — actual measured height is typically 0.2–0.5 inches below the nominal. Use the Inches Direct tab to calculate exact height for any floatation size.

Frequently Asked Questions

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