Part of the data ring
TireFit
Size sheet · one designationOutside the usual envelope

195/80R19
tyre size, drawn to scale

The dimensions

Size elevation 195/80R19 · SCALE 1:3
OVERALL Ø 795 mm / 31.28″ RIM 19″ = 482.6 mm SECTION 195 MM / 7.68″ SIDEWALL 156 mm 80% OF 195 MM 195/80R19

SOURCE·Metric size geometry + UN ECE R39 speedometer tolerance·drawn to scale from the size designation — 1 px = 2.87 mm·REVIEWED ETRTO STANDARD

795 mm A 195/80R19 stands 795 mm — 31.28″ — from the ground to the top of the tread, on a sidewall of 156.0 mm.

Every one of those figures comes out of the designation itself: 195 mm across, a sidewall 80% of that, beaded onto a 19-inch wheel. It turns 401 times per kilometre, which is the number your speedometer and ABS are really counting.

Overall diameter
795mm · 31.28″
Sidewall height
156.0mm
Section width
195mm · 7.68″
Revolutions / km
401· 645/mi

How the figures are derived

  1. Read the size as the specification it is: section width in millimetres, aspect ratio as a percentage of that width, rim diameter in inches.
  2. Sidewall height = width × aspect ÷ 100. This is the number the size string is really about, and it is the one nobody quotes.
  3. Overall diameter = rim × 25.4 + two sidewalls — one at the top of the wheel and one at the bottom.
  4. Circumference = π × overall diameter, which gives revolutions per kilometre and per mile directly.
  5. Nothing above is measured, estimated, averaged or dated. It is the definition of the designation, so it does not go stale and it has no source to cite beyond the standard itself.
sidewall (mm) = width × aspect ÷ 100
overall diameter (mm) = rim × 25.4 + 2 × sidewall
speedo true speed = indicated × (new diameter ÷ old diameter)

The full method, the ±3% rule, and what geometry cannot tell you →

What the three numbers actually say

The size on your sidewall is a specification, and each field of it means one thing.

195
Section width, 195 millimetres. The tyre's width at its widest point when it is mounted and inflated — sidewall bulge included, not the tread. In inches that is 7.68″.
80
Aspect ratio, 80%. The sidewall is 80% as tall as the tyre is wide, so 195 × 80 ÷ 100 = 156.0 mm. A lower number is a shorter sidewall and a stiffer ride.
R19
Radial construction, 19-inch rim. The R is the carcass type, not a size. The 19 is the wheel diameter the tyre beads onto — 482.6 mm — and it is the one dimension of the three that is still in inches.

The load index and speed symbol that follow the size — the 91V part — are a separate code. Read the rest of the sidewall →

Full dimensions

Overall diameter794.6 mm31.28″
Sidewall height156.0 mm6.14″
Section width195 mm7.68″
Rim diameter19″482.6 mm
Rolling circumference2496 mm2.496 m
Revolutions per kilometre400.6644.7 per mile
Ride height contribution397.3 mmhub centre to ground, unloaded

SOURCE·Metric size geometry + UN ECE R39 speedometer tolerance·computed from the 195/80R19 designation — no catalogue, no measurement, no vintage·REVIEWED ETRTO STANDARD

What else fits where a 195/80R19 does

Every size within reach of 795 mm, closest first, judged against the ±3% convention.

AlternativeDiameter ChangeVerdictSpeedo at 100
225/65R19 775 mm −2.45% Within tolerance 97.5 km/h true
225/60R20 778 mm −2.09% Within tolerance 97.9 km/h true
215/65R19 762 mm −4.09% Marginal 95.9 km/h true
205/65R19 749 mm −5.73% Outside tolerance 94.3 km/h true
225/60R19 753 mm −5.29% Outside tolerance 94.7 km/h true

Ranked by how close each one holds the original rolling diameter — which is the only thing this table can rank on. Whether any of them clears your arches, suits your rim width or carries your car's load is decided by the placard on your door pillar, not by this list.

What each one does to the speedometer

Assuming the car was calibrated for 195/80R19 and you fit the alternative instead. Indicated 100 km/h in every row.

Fitted insteadDiameter changeSpeedo shows 100True speedReads
225/65R19 −2.45%100 km/h97.5 km/h high — you are slower than shown
225/60R20 −2.09%100 km/h97.9 km/h high — you are slower than shown
215/65R19 −4.09%100 km/h95.9 km/h high — you are slower than shown

Reading low is the direction with no legal tolerance in it. Why that is, and what the rule says where you live →

195/80R19 — the questions that follow

What is the overall diameter of a 195/80R19 tyre?

795 mm, or 31.28″. That is the 19-inch rim (482.6 mm) plus two sidewalls of 156.0 mm each — one above the wheel centre and one below.

How tall is the sidewall on a 195/80R19?

156.0 mm. The 80 in the size is a percentage, not a measurement: the sidewall is 80% of the 195 mm section width, so 195 × 80 ÷ 100 = 156.0 mm.

What can I fit instead of a 195/80R19?

The closest alternatives on rolling diameter are 225/65R19 (−2.45%), 225/60R20 (−2.09%), 215/65R19 (−4.09%). Anything within ±3% of 795 mm keeps the speedometer and stability systems inside the band they were calibrated for — but arch clearance, rim width and load rating are separate questions that a size string cannot answer.

How many times does a 195/80R19 turn in a kilometre?

401 revolutions per kilometre, or 645 per mile. Its rolling circumference is 2.496 m, which is what the speedometer and the ABS both count against.

The geometry here is exact; whether a tyre fits YOUR car is not something geometry can answer. Arch clearance, suspension travel, offset, load rating and your vehicle's own placard all decide that, and none of them are in a size string. The ±3% rule quoted throughout is an industry convention, not a law. Confirm any change against the tyre placard on your door pillar and with a tyre fitter before you buy.

See all 10 sites in this family, with what each one answers

Published by

Amit Sharma

Auckland real-estate agent and marketer. Builds free, sourced data tools.