275/45R21 tire size
A 275/45R21 tire is 275 mm wide with a 123.8 mm sidewall, 45% of the width, on a 21-inch rim, which puts the whole tire at 780.9 mm, or about 30.7 inches, tall. Our data lists 1 models fitted with it from the factory, mostly PPV SUVs.
Overall height
780.9 mm
30.7 in
Sidewall
123.8 mm
45%
Circumference
2,453 mm
Revs per km
408
Actual dimensions of 275/45R21
| Section width | 275 mm (10.8 in) |
| Sidewall height | 123.8 mm (4.87 in) |
| Rim diameter | 21 in (533.4 mm) |
| Overall diameter | 780.9 mm (30.7 in) |
| Circumference | 2,453 mm |
| Revolutions per km | 408 |
| Inch notation (height x width) | 30.7x10.8R21 |
Worked out: sidewall 275 x 0.45 = 123.75 mm, rim 21 x 25.4 = 533.4 mm, overall 533.4 + (123.75 x 2) = 780.9 mm, circumference 3.1416 x 780.9 = 2,453 mm. One turn of the tire moves the car about 2.45 m, which is 408 turns per kilometer. New to sidewall codes? See how to read a tire size.
These are nominal figures from the standard formula. Real tires vary slightly by brand and squat a little under the weight of the car.
Cars fitted with 275/45R21 from the factory
Models whose Thai-market specification lists 275/45R21; the source column links to the spec we checked.
| Model | Years | Grades | Source |
|---|---|---|---|
| Ford Everest | 2022–present | Platinum V6 | headlightmag.com |
Cars that can switch to 275/45R21
These cars leave the factory on another size within 3% of the height of 275/45R21. Whether it fits still depends on rim width and wheel-well clearance.
| Model | Factory size | Height difference | Wheel |
|---|---|---|---|
| Isuzu MU-X2021–present | 265/50R20 | +1.02% | Needs 21-inch wheels |
Sizes that can replace 275/45R21
Sizes within ±3% of the overall height of 275/45R21. “At 100 km/h” is the real speed when the speedometer reads 100.
| Size | Height | Difference | At 100 km/h | Sidewall | Match | Compare |
|---|---|---|---|---|---|---|
| 275/50R20 | 783.0 mm | +2.1 mm (+0.27%) | 100.3 km/h | 137.5 mm | Very close | Compare |
| 255/55R20 | 788.5 mm | +7.6 mm (+0.97%) | 101.0 km/h | 140.3 mm | Close | Compare |
| 265/50R20 | 773.0 mm | −7.9 mm (−1.01%) | 99.0 km/h | 132.5 mm | Close | Compare |
| 285/50R20 | 793.0 mm | +12.1 mm (+1.55%) | 101.5 km/h | 142.5 mm | Close | Compare |
| 255/50R20 | 763.0 mm | −17.9 mm (−2.29%) | 97.7 km/h | 127.5 mm | Within range | Compare |
- The closest is 275/50R20 at 783.0 mm, +2.1 mm (+0.27%) from the original. With the speedometer on 100 km/h, the car would actually be doing about 100.3 km/h. Ground clearance rises by about 1.1 mm.
- Going down to 20-inch wheels, 275/50R20 (+0.27%) is the closest match and raises the sidewall to 137.5 mm.
Buying 275/45R21 tires
Pickup sizes like this come in quieter, softer H/T tread for paved roads and A/T tread for gravel, which costs more and is noisier. Choose for the roads you actually drive.
Check the production date in the DOT code before paying.
Check current prices
Search by brand
Links open marketplace search results; prices change constantly and not every brand makes this size.
Load index and speed rating for 275/45R21
The code after the size on the sidewall, as in 275/45R21 107S, is the load index and speed symbol. The common ratings for this size:
| Version | Index | Per tire | Four tires |
|---|---|---|---|
| Standard load (SL) | 107 | 975 kg | 3,900 kg |
| Extra load (XL) | 110 | 1,060 kg | 4,240 kg |
The new tire's load index and speed symbol must be no lower than the door placard, and it only carries its rated load at the correct pressure.
Common speed symbols in this size
S
180 km/h
T
190 km/h
H
210 km/h
275/45R21 questions
How tall is a 275/45R21 tire?
About 30.7 inches, or 780.9 mm, from top to bottom before it carries weight. Each sidewall is 123.8 mm tall and the tire is 275 mm (10.8 in) wide.
Which cars use 275/45R21 tires?
From Thai-market specifications, 275/45R21 comes on Ford Everest.
Can I fit 275/50R20 instead of 275/45R21?
Size-wise, yes: the height differs by +0.27% (+2.1 mm), so an indicated 100 km/h is really about 100.3 km/h. It also needs 20-inch wheels. Check rim width and load index first.
How much weight can a 275/45R21 tire carry?
Most standard-load versions carry load index 107: 975 kg per tire, 3,900 kg across four. XL versions are rated 110, or 1,060 kg per tire. Look for the number after the size on the sidewall, as in 275/45R21 107S.
To compare other sizes yourself, use the tire size calculator; changing rim size, try plus/minus sizing; and see speedometer error by speed.