17-inch rim · tyre size comparison

215/45 R17 vs 225/45 R17

225/45 R17 is 9 mm (0.35 in) taller than 215/45 R17, a +1.44% difference in overall diameter. That is inside the ±3% limit commonly used to screen a tire size change; it is a nominal calculation, not a fitment approval.

Diameter difference
+9 mm
+0.35 in · +1.44%
Indicated 70 mph
71 mph
Actual speed on 225/45 R17, if the speedometer was accurate on 215/45 R17.
Sidewall height
+4.5 mm
96.75 mm to 101.25 mm.
Compare in the calculator215/45 R17 size guide225/45 R17 size guideSpeedometerWhat changes

Dimensions side by side

215/45 R17 and 225/45 R17 dimensions
Measurement215/45 R17225/45 R17Difference
Overall diameter625.3 mm24.62 in634.3 mm24.97 in+9 mm (+1.44%)+0.35 in
Section width215 mm8.46 in225 mm8.86 in+10 mm+0.39 in
Sidewall height96.75 mm3.81 in101.25 mm3.99 in+4.5 mm+0.18 in
Circumference1,964.44 mm77.34 in1,992.71 mm78.45 in+28.27 mm+1.11 in
Rim diameter431.8 mm17 in431.8 mm17 in0 mm0 in
Revolutions per mile819.24807.61-11.62
Revolutions per km509.05501.83-7.22
215/45 R17225/45 R17
Nominal diameters at the same scale. The inner circle is the rim.

Calculated from the nominal size codes, without load or tread wear. Real tyres vary by model, rim width and pressure, so the exact tyre's published dimensions take priority.

Speedometer with 225/45 R17

If the speedometer was accurate on 215/45 R17, fitting 225/45 R17 means the car is travelling 1.44% faster than it shows, and the odometer under-records distance by about the same amount.

Indicated speed versus calculated road speed on 225/45 R17
Speedometer showsActual on 225/45 R17Difference
30 mph30.43 mph+0.43 mph
50 mph50.72 mph+0.72 mph
60 mph60.86 mph+0.86 mph
70 mph71.01 mph+1.01 mph
50 km/h50.72 km/h+0.72 km/h
100 km/h101.44 km/h+1.44 km/h

UN ECE Regulation 39, used in the UK and EU, does not allow a speedometer to show less than the true speed, so many read slightly high from the factory. A taller tyre uses up some of that margin. Calibration varies by car; these figures are the tyre-size effect only.

What changes from 215/45 R17 to 225/45 R17

  • Wheels

    Both fit 17-inch wheels. Our rim-width starting estimate is 6.5 to 7.5 inches for 215/45 R17 and 7 to 8 inches for 225/45 R17, so a 7 to 7.5-inch wheel sits in both ranges. The exact tyre's approved rim range takes priority.

  • Sidewall and ride comfort

    225/45 R17 has 4.5 mm more sidewall (101.25 vs 96.75 mm). A taller sidewall usually rides a little softer and gives the rim more protection from potholes and kerbs, at the cost of some steering sharpness.

  • Contact width

    225/45 R17 is 10 mm wider in nominal section width (4.7%). A wider tyre usually puts a wider, shorter contact patch on the road, which can help dry grip, but it may follow ruts more, clear standing water less readily and add some rolling resistance.

  • Wheel well clearance

    Ride height changes by about +4.5 mm, and the top of the tyre moves the same distance closer to the arch. On the same wheel width and offset, each sidewall moves about 5 mm further out towards the arch lip and further in towards the suspension. Check clearance at full steering lock and full suspension compression, especially on a lowered car.

  • Gearing

    The effective final drive changes by -1.42%: 3,000 rpm at a given road speed becomes about 2,960 rpm. Gearing gets slightly longer, so cruising revs drop and acceleration in each gear softens.

  • ABS, stability control and AWD

    These systems compare wheel speeds. Fit the same size on both ends of an axle; with a 1.4% diameter gap, never mix 215/45 R17 and 225/45 R17 on an AWD car, and follow the car maker's rolling-circumference limits, which can be much tighter than 3%.

General tendencies from the nominal numbers, not a test of any tyre. Load index, speed rating, tyre construction and the car's approved sizes matter more than these rules of thumb.

Explained in our guides

Cars in our guides using these sizes

Factory trims and popular community setups from our fitment guides. A popular setup is not a factory approval; each guide explains its trims, axles and clearance limits.

215/45 R17

225/45 R17

More comparisons

215/45 R17 compared

205/55 R16 vs 215/45 R17205/45 R17 vs 215/45 R17205/50 R17 vs 215/45 R17215/40 R17 vs 215/45 R17215/45 R17 vs 215/50 R17

225/45 R17 compared

205/50 R17 vs 225/45 R17225/45 R17 vs 245/40 R17225/45 R17 vs 235/45 R17225/45 R17 vs 235/40 R17225/45 R17 vs 225/50 R17225/45 R17 vs 225/55 R17

Questions

Can I use 225/45 R17 instead of 215/45 R17?

Both fit 17-inch wheels. The diameter difference is +1.44%, inside the ±3% screening limit. That does not approve fitment: check the car maker's approved sizes, load index, speed rating, rim width and clearance first.

How much bigger is 225/45 R17 than 215/45 R17?

Overall diameter is 9 mm (0.35 in) larger: 634.3 vs 625.3 mm. Section width is 10 mm wider, and the sidewall is 4.5 mm taller. These are nominal figures; real tyres vary by model and rim width.

Will 225/45 R17 change my speedometer reading?

Yes, by 1.44%. If the speedometer was accurate on 215/45 R17, an indicated 60 mph would be about 60.9 mph on 225/45 R17, and an indicated 100 km/h about 101.4 km/h. You would be going faster than the speedometer shows.

Which is better, 215/45 R17 or 225/45 R17?

Neither in general. 225/45 R17 has the taller sidewall, which usually rides more comfortably; 215/45 R17 usually steers more sharply. 225/45 R17 is wider, which can help dry grip; the narrower size is usually better in standing water and snow. The size listed for your car's trim, on its placard or in the handbook, is the safe default.

Check the exact tyre

Size codes give nominal dimensions. Before buying, confirm the size is approved for your car and check the exact tyre's load and speed ratings and published dimensions.

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