255/30 R21 Tyres in Park Royal

255 mm wide, 30% profile, for a 21-inch wheel. Fitted at our NW10 workshop, with live prices online.

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255/30 R21 is a 21-inch tyre, 255 mm wide, with a sidewall 76.5 mm tall (30% of the width). We fit 255/30 R21 tyres at our Park Royal garage in NW10, with balancing, a new valve and disposal of the old tyre included. The price depends on the brand: see live prices for 255/30 R21.

What 255/30 R21 means

255 mmWidth
30%Aspect ratio (sidewall ÷ width)
21"Rim diameter (533.4 mm)
686.4 mmOverall diameter, new and unloaded
  • 255: the tyre is 255 mm wide, measured across the sidewalls.
  • 30: the sidewall height is 30% of the width, so 255 × 30% = 76.5 mm.
  • R: radial construction. A ZR in the same place is the same size with a speed marking for over 240 km/h.
  • 21: it fits a 21-inch wheel. Overall diameter is 21 × 25.4 mm plus two sidewalls: 686.4 mm.

The load index and speed rating follow the size on the sidewall (for example 91V). Replace like for like or higher, as your handbook states.

What to look for in a 255/30 R21 tyre

  • Low profile, less cushion. A 76.5 mm sidewall on a 21-inch wheel leaves little to absorb a pothole or a kerb, so check for bulges and rim damage after a hard hit, and have the wheel alignment checked if the steering pulls or the new tyres wear on one edge.
  • Winter or all-season. If you want winter or all-season tyres in 255/30 R21, the live list shows what is made in this size today; not every pattern is made in every size.

255/30 R21 tyres by price band

These are the brands we fit, by price band. Which of them make 255/30 R21, and at what price today, is on the live price list.

Prices for 255/30 R21 depend on the brandsee live fitted prices for 255/30 R21.

Book online, call 020 3886 2355 or WhatsApp 07476 586 589. We fit at Unit 4 Unimix House, Abbey Road, Park Royal, London, NW10 7TR, balancing and a new valve included.

Sizes next to 255/30 R21

Same 21-inch rim, one step wider, narrower, taller or lower.

Sizes with a similar overall diameter

These sizes are within 3% of the 686.4 mm diameter of 255/30 R21 on paper, and within 20 mm of its width. That alone does not make them approved for your car: check the handbook or the door placard, and keep one size across an axle.

SizeOverall diameterDifference
255/35 R20686.5 mm+0.0%
245/35 R20679.5 mm-1.0%
235/40 R20696 mm+1.4%
275/30 R21698.4 mm+1.8%
235/35 R20672.5 mm-2.0%
275/25 R21670.9 mm-2.3%

See all tyre sizes, or read how our tyre fitting works.

Frequently asked questions

Is 255/30 R21 the same as 255/30 ZR21?

Yes, the dimensions are the same. The Z marks a tyre rated for over 240 km/h (149 mph); the exact rating is the letter after the load index, such as W or Y. Fit at least the speed rating your handbook gives for the car.

Can I fit 255/35 R20 instead of 255/30 R21?

Only if 255/35 R20 is listed for your car. On paper it is 686.5 mm tall against 686.4 mm for 255/30 R21, a 0.0% difference, so the speedometer would barely change. It also needs a 20-inch wheel instead of a 21-inch one. Wheel width, arch clearance, load index and speed rating must suit the car too, so check the handbook or the door placard, and fit one size across an axle.

How tall is a 255/30 R21 tyre?

About 686.4 mm (27.0 inches) across when new and unloaded: the 21-inch rim (533.4 mm) plus two sidewalls of 76.5 mm, which is 30% of the 255 mm width. Real tyres differ by a few millimetres between brands and patterns.

Same-Day Tyre Fitting & Walk-Ins Welcome

New tyres fitted while you wait, plus puncture repairs, wheel balancing and battery replacement at our Park Royal workshop. No appointment needed for tyres, just call in.

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