245/40R20 tire size
A 245/40R20 tire is 245 mm wide with a 98.0 mm sidewall, 40% of the width, on a 20-inch rim, which puts the whole tire at 704.0 mm, or about 27.7 inches, tall. No model in our data leaves the factory on it, but it can replace the original size on 6 models within 3% of the height.
Overall height
704.0 mm
27.7 in
Sidewall
98.0 mm
40%
Circumference
2,212 mm
Revs per km
452
Actual dimensions of 245/40R20
| Section width | 245 mm (9.6 in) |
| Sidewall height | 98.0 mm (3.86 in) |
| Rim diameter | 20 in (508.0 mm) |
| Overall diameter | 704.0 mm (27.7 in) |
| Circumference | 2,212 mm |
| Revolutions per km | 452 |
| Inch notation (height x width) | 27.7x9.6R20 |
Worked out: sidewall 245 x 0.4 = 98 mm, rim 20 x 25.4 = 508 mm, overall 508 + (98 x 2) = 704.0 mm, circumference 3.1416 x 704.0 = 2,212 mm. One turn of the tire moves the car about 2.21 m, which is 452 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 245/40R20 from the factory
No model sold in Thailand in our data leaves the factory on 245/40R20.
Cars that can switch to 245/40R20
These cars leave the factory on another size within 3% of the height of 245/40R20. Whether it fits still depends on rim width and wheel-well clearance.
| Model | Factory size | Height difference | Wheel |
|---|---|---|---|
| BYD Seal2023–present | 235/45R19 | +1.43% | Needs 20-inch wheels |
| Toyota Yaris Cross HEV2023–present | 215/55R18 | +1.48% | Needs 20-inch wheels |
| Mazda CX-302020–present | 215/55R18 | +1.48% | Needs 20-inch wheels |
| BYD ATTO 32022–present | 215/55R18 | +1.48% | Needs 20-inch wheels |
| MG HS / HS PHEVCurrent model | 235/50R18 | +1.70% | Needs 20-inch wheels |
| BYD Sealion 6 DM-i2024–present | 235/50R19 | −1.90% | Needs 20-inch wheels |
Sizes that can replace 245/40R20
Sizes within ±3% of the overall height of 245/40R20. “At 100 km/h” is the real speed when the speedometer reads 100.
| Size | Height | Difference | At 100 km/h | Sidewall | Match | Compare |
|---|---|---|---|---|---|---|
| 245/45R19 | 703.1 mm | −0.9 mm (−0.13%) | 99.9 km/h | 110.3 mm | Very close | Compare |
| 255/45R19 | 712.1 mm | +8.1 mm (+1.15%) | 101.2 km/h | 114.8 mm | Close | Compare |
| 235/45R19 | 694.1 mm | −9.9 mm (−1.41%) | 98.6 km/h | 105.8 mm | Close | Compare |
| 235/50R19 | 717.6 mm | +13.6 mm (+1.93%) | 101.9 km/h | 117.5 mm | Close | Compare |
| 255/40R19 | 686.6 mm | −17.4 mm (−2.47%) | 97.5 km/h | 102.0 mm | Within range | Compare |
| 255/35R20 | 686.5 mm | −17.5 mm (−2.49%) | 97.5 km/h | 89.3 mm | Within range | Compare |
| 225/45R19 | 685.1 mm | −18.9 mm (−2.68%) | 97.3 km/h | 101.3 mm | Within range | Compare |
- Keeping your wheels, the closest is 255/35R20 at 686.5 mm, −17.5 mm (−2.49%) from the original. With the speedometer on 100 km/h, the car would actually be doing about 97.5 km/h. Ground clearance drops by about 8.8 mm.
- Going down to 19-inch wheels, 245/45R19 (−0.13%) is the closest match and raises the sidewall to 110.3 mm.
Buying 245/40R20 tires
Low-profile sizes are mostly performance tires and price rises with W or Y speed ratings; comfort-focused models exist in the same size if you do not drive hard.
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 245/40R20
The code after the size on the sidewall, as in 245/40R20 95V, is the load index and speed symbol. The common ratings for this size:
| Version | Index | Per tire | Four tires |
|---|---|---|---|
| Standard load (SL) | 95 | 690 kg | 2,760 kg |
| Extra load (XL) | 99 | 775 kg | 3,100 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
V
240 km/h
W
270 km/h
Y
300 km/h
245/40R20 questions
How tall is a 245/40R20 tire?
About 27.7 inches, or 704.0 mm, from top to bottom before it carries weight. Each sidewall is 98.0 mm tall and the tire is 245 mm (9.6 in) wide.
Which cars use 245/40R20 tires?
No car in our data is fitted with 245/40R20 from the factory, but its height is close to the original size on BYD Seal, Toyota Yaris Cross HEV, Mazda CX-30, BYD ATTO 3 and MG HS / HS PHEV, so it works as a replacement size.
Can I fit 255/35R20 instead of 245/40R20?
Size-wise, yes: the height differs by −2.49% (−17.5 mm), so an indicated 100 km/h is really about 97.5 km/h. The tread is 10 mm wider. Check rim width and load index first.
How much weight can a 245/40R20 tire carry?
Most standard-load versions carry load index 95: 690 kg per tire, 2,760 kg across four. XL versions are rated 99, or 775 kg per tire. Look for the number after the size on the sidewall, as in 245/40R20 95V.
Other 20-inch sizes
To compare other sizes yourself, use the tire size calculator; changing rim size, try plus/minus sizing; and see speedometer error by speed.