275/50R21
Overall diameter
31.83″
808 mm
Sidewall height
5.41″
137.5 mm
Tread width
275 mm
10.8″
Circumference
99.99″
8.3 ft
Revs per mile
634
394 per km
Wheel diameter
21″
aspect ratio 50%
Cross-section
- Overall diameter
- 31.83″
- Sidewall (each side)
- 5.41″
- Wheel
- 21″
275/50R21 compared with other sizes
All 26 practical swaps involving 275/50R21 — diameter change, speedometer impact and a fit verdict for each.
275/50R21 → 275/55R20
275/55R20
Diameter −0.3% · Good fit
275/50R21 → 265/55R20
265/55R20
Diameter +1.1% · Good fit
275/50R21 → 305/50R20
305/50R20
Diameter −0.6% · Good fit
275/50R21 → 265/45R21
265/45R21
Diameter +4.7% · Marginal fit — proceed with care
275/50R21 → 275/45R21
275/45R21
Diameter +3.5% · Marginal fit — proceed with care
275/45R21 → 275/50R21
275/45R21
Diameter −3.4% · Marginal fit — proceed with care
285/45R21 → 275/50R21
285/45R21
Diameter −2.3% · Good fit
275/55R20 → 275/50R21
275/55R20
Diameter +0.3% · Good fit
265/45R21 → 275/50R21
265/45R21
Diameter −4.5% · Marginal fit — proceed with care
305/50R20 → 275/50R21
305/50R20
Diameter +0.6% · Good fit
285/45R22 → 275/50R21
285/45R22
Diameter +0.9% · Good fit
265/55R20 → 275/50R21
265/55R20
Diameter −1.1% · Good fit
285/55R20 → 275/50R21
285/55R20
Diameter +1.6% · Good fit
275/55R19 → 275/50R21
275/55R19
Diameter −2.9% · Good fit
275/50R22 → 275/50R21
275/50R22
Diameter +3.1% · Marginal fit — proceed with care
285/50R20 → 275/50R21
285/50R20
Diameter −1.9% · Good fit
265/60R20 → 275/50R21
265/60R20
Diameter +2.2% · Good fit
275/60R20 → 275/50R21
275/60R20
Diameter +3.7% · Marginal fit — proceed with care
275/40R22 → 275/50R21
275/40R22
Diameter −3.7% · Marginal fit — proceed with care
275/50R21 → 285/45R21
285/45R21
Diameter +2.3% · Good fit
275/50R21 → 275/40R22
275/40R22
Diameter +3.8% · Marginal fit — proceed with care
275/50R21 → 275/50R22
275/50R22
Diameter −3.0% · Marginal fit — proceed with care
275/50R21 → 285/40R22
285/40R22
Diameter +2.7% · Good fit
275/50R21 → 285/45R22
285/45R22
Diameter −0.8% · Good fit
275/50R21 → 285/50R22
285/50R22
Diameter −4.2% · Marginal fit — proceed with care
275/50R21 → 305/45R22
305/45R22
Diameter −3.0% · Good fit
Common questions
- What is the overall diameter of a 275/50R21 tire?
- A 275/50R21 tire is about 31.83″ (808 mm) in overall diameter, with a sidewall height of 137.5 mm and a circumference of 99.99″.
- How many revolutions per mile does a 275/50R21 tire turn?
- A 275/50R21 turns roughly 634 revolutions per mile (394 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
- What do the numbers in 275/50R21 mean?
- 275 is the tread width in millimetres, 50 is the aspect ratio — the sidewall height as a percentage of the tread width — and 21 is the wheel diameter in inches. So the sidewall is 275 × 50% = 137.5 mm tall.