185/65R15 vs 205/65R14 tire size comparison

Change either size and everything below updates.

Start from your car make, model, year
Current tire size
/R
xR
New tire size
/R
xR

Width in mm · aspect = sidewall height as a % of width · rim in inches

Flotation (LT) sizes, all in inches: overall diameter × section width, then rim

185/65R15: 24.47″ (622 mm) tall, 7.28″ (185 mm) wide, sidewall 4.73″ (120 mm) — 824 revolutions per mile.

Well within tolerance

+0.10% diameter

The overall diameter changes by less than 1.5%, so speedometer error is negligible and ride height barely moves.

  • Needs 14″ wheels: this tire does not fit your 15″ rims.
  • 20 mm wider: check inner clearance and that your rims are wide enough.

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Measurement185/65R15205/65R14Diff%
Overall diameter24.47″622 mm24.49″622 mm+0.02″+0.1%
Section width185.0 mm205.0 mm+20.0 mm+10.8%
Sidewall height120.3 mm133.3 mm+13.0 mm+10.8%
Rim diameter15″14″−1″−6.7%
Circumference76.87″1952 mm76.94″1954 mm+0.07″+0.1%
Revolutions per mileturns per distance; drives the odometer824512 /km823512 /km−1−0.1%
Ride height change——+0.01″ +0.3 mm

Speedometer reading

Speedo shows
60mph
97 km/h
Actual speed
60.1mph
97 km/h

Overlay

185/65R15205/65R14

Plus sizing: 185/65R15 on smaller or bigger wheels

Sizes fitted to cars that keep the overall diameter within 3% of 185/65R15 on a rim one inch smaller or up to two inches bigger, closest first.

RimSizeDiameterChangeCompare
R14 (−1) 205/65R14 24.49″ +0.1% Compare
165/80R14 24.39″ −0.3% Compare
R16 (+1) 195/55R16 24.44″ −0.1% Compare
215/50R16 24.46″ 0.0% Compare
R17 (+2) 175/55R17 24.58″ +0.5% Compare
185/50R17 24.28″ −0.8% Compare

How to use the tire size calculator

Put your current tire size — width, aspect ratio and rim diameter — into the first form, then your desired size into the second. You’ll get the difference between the new and the old size, plus the speedometer reading difference and your actual speed on the new set. Both metric and flotation (LT inch) sizes are supported.

The calculator helps you decide whether a set of tires and wheels will fit your car. To compare tires by brand and model instead, use our tire comparison tool; to look up factory sizes, browse by car make.

Changing wheels too? The wheel offset calculator shows how far a new wheel width and offset move the tire toward the suspension and the fender.

Reading a tire size

225/45R17
225
Section width in millimetres
45
Aspect ratio — sidewall height as a % of width
R
Radial construction
17
Rim diameter in inches

Full guide to the tire sidewall →

Sizes often compared with 185/65R15