Tire size

255/50 R19

Full dimensions and a live comparison calculator for the 255/50 R19 tire size.

Overall diameter

737.6 mm

29.04″

Sidewall height

127.5 mm

Circumference

2.317 m

Revs / km

431.5

Section width

255 mm

Aspect ratio

50%

Rim diameter

19″

482.6 mm

Radius

368.8 mm

What does 255/50 R19 mean?

The 255 is the section width in millimetres, measured sidewall to sidewall. The 50 is the aspect ratio — sidewall height as a percentage of width, so the sidewall here is 127.5 mm. The R19 means a radial-construction tire designed for a 19-inch wheel rim. Together these give an overall diameter of 738 mm.

Compare 255/50 R19 with another size

Current Tire

255/50R19

New Tire

225/45R17
255/50 R19
225/45 R17

Ground line · scaled comparison

Not Recommended

Over 5% — speedometer & ABS may misread

Diameter change

-103.3 mm

-14.00%

Speedometer at 100

86.0 km/h

-14.00% error

Ground clearance

-51.6 mm

ride height delta

Sidewall change

-26.3 mm

revs/km: 501.8

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Common alternatives to 255/50 R19

These sizes are within a few percent overall diameter — usually safe on the same vehicle from a speedometer-error standpoint.

Compare 255/50 R19 with popular upgrades

Plus-size upgrades from 255/50 R19

255/45 R20Ø 738 mm

-0.01% vs 255/50 R19

Compare →
295/35 R21Ø 740 mm

+0.31% vs 255/50 R19

Compare →
285/35 R21Ø 733 mm

-0.64% vs 255/50 R19

Compare →
295/40 R20Ø 744 mm

+0.87% vs 255/50 R19

Compare →
265/40 R21Ø 745 mm

+1.06% vs 255/50 R19

Compare →
245/45 R20Ø 729 mm

-1.23% vs 255/50 R19

Compare →

Fitment safety note

Overall diameter, speedometer error and circumference are only part of the picture. Physical clearance, wheel offset (ET), hub bore, suspension geometry, load index and your manufacturer's recommendation all decide whether a size is truly safe on your car. Always cross-check with the vehicle manual or a qualified fitter before changing tire size.

Frequently asked questions

All 19″ tire sizes →Speedometer error guide →Safe size difference guide →