125/80R13 vs 145/80R13 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

125/80R13: 20.87″ (530 mm) tall, 4.92″ (125 mm) wide, sidewall 3.94″ (100 mm) — 966 revolutions per mile.

Outside the 3% rule

+6.04% diameter

This exceeds the tolerance most manufacturers allow. Expect speedometer error, possible rubbing, and on some cars ABS or stability-control faults.

  • 20 mm wider: check inner clearance and that your rims are wide enough.

Check what fits your car Factory tire sizes for every make, model and year.

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Measurement125/80R13145/80R13Diff%
Overall diameter20.87″530 mm22.13″562 mm+1.26″+6.0%
Section width125.0 mm145.0 mm+20.0 mm+16.0%
Sidewall height100.0 mm116.0 mm+16.0 mm+16.0%
Rim diameter13″13″0″0.0%
Circumference65.58″1666 mm69.54″1766 mm+3.96″+6.0%
Revolutions per mileturns per distance; drives the odometer966600 /km911566 /km−55−5.7%
Ride height change——+0.63″ +16.0 mm

Speedometer reading

Speedo shows
60mph
97 km/h
Actual speed
63.6mph
102 km/h

Overlay

125/80R13145/80R13

Plus sizing: 125/80R13 on smaller or bigger wheels

Sizes fitted to cars that keep the overall diameter within 3% of 125/80R13 on a rim one inch smaller or up to two inches bigger, closest first.

RimSizeDiameterChangeCompare
R14 (+1) 155/55R14 20.71″ −0.8% Compare
155/60R14 21.32″ +2.2% 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 and backspacing 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 →