Go kart tire size chart, and how to read the numbers
12 min Updated how-to
A go kart tire size like 10 x 4.50-5 reads overall diameter x section width - rim diameter, all in inches: about 10 inches tall, about 4.5 inches wide, on a 5-inch rim. Sprint racing karts run 10-inch fronts and 11-inch rears on 5-inch rims, yard and off-road karts run 13 to 22 inch tires on 6, 7, 8 or 10 inch rims, and ride-ons use small urethane or airless wheels. The chart below lists the common sizes by kart type, along with the real dimensions that tire makers publish, because the printed size is nominal and real tires can differ from it by as much as 5 percent.
How to read a go kart tire size
Most kart tires carry three numbers in a fixed order: height, then width, then rim diameter. The x and the dash are separators, not math, and only the last number has to match your wheel exactly.
Three-number sizes: 10 x 4.50-5, 11 x 7.10-5, 13 x 5.00-6
- First number, overall diameter. The tire’s height in inches when mounted and inflated. It is a nominal figure. MG’s spec table for its SM2 racing tire lists the 11 x 7.10-5 rear at 272 mm, which is 10.7 inches, and the 10 x 4.60-5 front at 260 mm, or 10.2 inches.
- Second number, section width. Nominal width in inches. The real width depends on the rim: that same MG rear measures 210 mm (8.3 inches) across on a 202 mm rim, well past what 7.10 suggests.
- Third number, rim diameter. The bead seat diameter in inches. A 5 fits a 5-inch wheel and nothing else.
Some brands print racing sizes width first, as 4.50/10.0-5 or 7.1/11.0-5. The figure near 10 or 11 is still the diameter.
Slash and two-number sizes: 4.10/3.50-4, 3.50-6 and 10 x 2.75
A code like 4.10/3.50-4, common on mini bikes, hand trucks and small karts, contains no diameter at all. It is a dual width marking: the same tire replaces either a 4.10-4 or a 3.50-4, and the 4 is the rim diameter. One popular shortcut adds the section height twice to the rim and gets 11 inches, but Kenda’s K500 Super Turf in this size is listed at 272 mm (10.7 inches) outside diameter, so measure before trusting the shortcut.
Two numbers joined by a dash, such as 3.50-6, mean width and rim. Two numbers joined by an x, such as the 10 x 2.75 inch rear Segway lists for its GoKart Pro 2, usually describe a solid or semi-solid tire by outside diameter and width.
Metric sizes: 145/70-6
The metric code is section width in millimeters / sidewall height as a percentage of width - rim diameter in inches. For 145/70-6 that is a 145 mm (5.7 inch) wide tire with a sidewall 70 percent as tall, or 101.5 mm (4.0 inches). Add two sidewalls to the 6-inch rim and the tire stands about 14.0 inches tall. Some catalogs describe it as 14.5 inches tall and 70 mm wide, which reads the aspect ratio as a width. Coleman’s spec page for the GK200 two-seater pairs a 145/70-6 front with a 16 x 8-7 rear, a typical off-road mix of metric and inch sizes.
Segway’s GoKart Pro 2 front tire uses the same logic: 80 mm wide at 60 percent on a 5-inch hub works out to about 8.8 inches tall.
The other markings on the sidewall
- Ply rating (2PR, 4PR). A strength rating that sets pressure and load limits: Carlstar rates its 2-ply 13x5.00-6 Super Lug at 20 psi and 290 lb, its 4-ply Smooth at 40 psi and 440 lb.
- TL or TT. Tubeless or tube type. A split rim needs a tube whatever the tire says.
- NHS. Not for highway service, the marking on tires built for off-road use only.
- Compound name or color on racing tires, such as MG’s SM2 (prime, medium) or SH2 (option, hard). Class rules care about this more than size.
Go kart tire size chart by kart type
The chart gives the front and rear size for each common kart type. Confirm against the sidewall of the tire you have, since manufacturers change sizes between model years.
| Kart type | Front | Rear | Rim diameter | Published by |
|---|---|---|---|---|
| Sprint racing, senior dry | 10 x 4.60-5 | 11 x 7.10-5 | 5 in | MG (SM2, SH2) |
| Sprint racing, other dry fronts | 10 x 4.50-5 | 11 x 7.10-5 | 5 in | several makers |
| Sprint racing, rain | 10 x 4.20-5 | 11 x 6.00-5 | 5 in | MG (SW2) |
| Mini and kid karts | 10 x 4.00-5 | 11 x 5.00-5 | 5 in | MG (SC2) |
| Rental and indoor fleets | 10 x 4.60-5 | 11 x 6.00-5 or 11 x 7.10-5 | 5 in | MG (RL2, RL3) |
| Small yard kart | 13 x 5-6 | 13 x 5-6 | 6 in | Coleman (GK100) |
| Two-seat off-road kart | 145/70-6 | 16 x 8-7 | 6 in / 7 in | Coleman (GK200) |
| Large off-road kart | 19 x 7-8 | 22 x 10-10 | 8 in / 10 in | Hammerhead (GTS 150) |
| Yard and off-road replacements | 13 x 5.00-6, 15 x 6.00-6 | 16 x 6.50-8, 18 x 9.50-8 | 6 in / 8 in | Carlstar |
| Compact electric kart | 80 mm, 60 percent, 5 in hub | 10 x 2.75 in solid | 5 in front | Segway (GoKart Pro 2) |
| Crazy Cart XL, ages 16+ | 8 x 2 in pneumatic | urethane casters | none | Razor |
| Crazy Cart Shift and Shuffle, kids | 6 in airless, 5 in urethane | urethane casters | none | Razor |
| Open-frame drift kart | rubber front tire | hard polymer sleeve over the rear wheel | matches rear wheel | sleeve maker |
| YAWKART mini drift cars | 8-inch drift set (stock), 10-inch set (option) | same | complete wheels | our catalogue |
Racing and rental tires: real dimensions
MG publishes measured dimensions for each size, which is the data you need for gearing and rim choice. Pressures are MG’s hot targets, plus or minus 0.20 bar (3 psi).
| MG tire | Size | Overall diameter | Mounted width | Rim width | Hot pressure |
|---|---|---|---|---|---|
| SM2, prime medium | 10 x 4.60-5 | 260 mm (10.2 in) | 130 mm | 122 mm | 0.80 bar (11.6 psi) |
| SM2, prime medium | 11 x 7.10-5 | 272 mm (10.7 in) | 210 mm | 202 mm | 0.80 bar (11.6 psi) |
| SH2, option hard | 10 x 4.60-5 / 11 x 7.10-5 | 260 / 272 mm | 130 / 210 mm | 120 / 202 mm | 1.00 bar (14.5 psi) |
| SW2, rain | 10 x 4.20-5 / 11 x 6.00-5 | 257 / 272 mm | 130 / 175 mm | 119 / 169 mm | 1.00 bar (14.5 psi) |
| SC2, mini | 10 x 4.00-5 / 11 x 5.00-5 | 255 / 264 mm | 115 / 145 mm | 102 / 134 mm | 1.00 bar (14.5 psi) |
| RL3, rental | 10 x 4.60-5 | 258 mm (10.2 in) | 132 mm | 120 mm | 1.10 bar (16 psi) |
| RL3, rental | 11 x 6.00-5 | 275 mm (10.8 in) | 180 mm | 180 mm | 1.10 bar (16 psi) |
| RL3, rental | 11 x 7.10-5 | 274 mm (10.8 in) | 210 mm | 205 mm | 1.10 bar (16 psi) |
Two things stand out. No “11-inch” rear in the table reaches 11 inches, and the narrower rental 11 x 6.00-5 is as tall as the 7.10. Width, not height, is what separates most rear sizes.
Yard and off-road tires: real dimensions
Carlstar’s spec sheets show how far a mounted yard tire can sit from its printed size. Its 15x6.00-6 Turf Saver, for example, mounts at 14.32 inches, not 15.
| Carlstar tire | Mounted diameter | Mounted width | Rim width | Max pressure | Load per tire |
|---|---|---|---|---|---|
| 13x5.00-6, 2-ply Super Lug | 13.08 in | 4.53 in | 3.50 in | 20 psi | 290 lb |
| 13x5.00-6, 4-ply Smooth | 12.72 in | 4.80 in | 3.50 in | 40 psi | 440 lb |
| 15x6.00-6, 2-ply Turf Saver | 14.32 in | 6.35 in | 4.50 in | 14 psi | 365 lb |
| 16x6.50-8, 2-ply Turf Saver | 16.25 in | 6.56 in | 5.38 in | 12 psi | 380 lb |
| 18x9.50-8, 2-ply Turf Saver | 17.76 in | 9.47 in | 7.00 in | 12 psi | 695 lb |
| 18x9.50-8, 4-ply Smooth | 17.80 in | 9.30 in | 7.00 in | 24 psi | 1,020 lb |
Rim width, bead and bolt pattern
Rim diameter decides whether a tire goes on; rim width decides whether it works. Each tire is designed around a rim width, and the tables above list it: MG’s 11 x 7.10-5 sits on a rim about 202 to 205 mm wide, its 11 x 6.00-5 on 169 to 180 mm, and Carlstar’s 8-inch sizes range from a 5.38-inch rim for the 16x6.50-8 to 7.00 inches for the 18x9.50-8. Same rim diameter, different wheel.
Racing rears are sold by width to suit the tire: Swift’s magnesium rears come in 212 mm for 7.1-inch tires and 180 mm for 6.0-inch tires. Swift also notes that a 6.0 tire on the wider wheel changes the mounted circumference, so gearing has to follow.
Bead. A 5-inch kart rim is not quite 5 inches at the bead: MG lists the bead diameter as 126.20 mm, against 127 mm for an exact 5 inches. Racing tires go on tight, and MG’s tire FAQ gives 42 to 56 psi as the most to use when first inflating a freshly mounted tire, before setting the running pressure.
Bolt pattern. Most racing hubs use the European 3/58 pattern: three studs on a 58 mm circle. Yard kart wheels vary. Azusa’s 5-inch split rear wheel for a 1-inch live axle uses a 3-3/4 inch bolt circle, and import wheels use their own. To measure a 3-hole wheel, take the center-to-center distance between two neighboring holes and multiply by 1.155; a 3/58 wheel measures about 50 mm hole to hole. On a 4-hole wheel, measure diagonally across the center. On a 5-hole wheel, multiply the neighbor-to-neighbor distance by 1.701.
Axle sizes and hub bores
Kart axles run from 1 inch on yard karts to 50 mm on racing chassis, and the axle decides which hubs, sprockets and brake rotors fit. Measure it before buying any wheel that bolts to a rear hub. Common sizes:
- 50 mm: the largest rear axle that CIK-derived racing rules allow, with a minimum wall of 1.9 mm. The usual size on current senior sprint chassis.
- 40 mm: the usual superkart size, and found on some other racing chassis.
- 30 mm: the cap in mini-kart rules, which offset the smaller tube with a thick 4.9 mm wall.
- 1-1/4 inch: still sold for American oval karts.
- 1 inch: the usual keyed live axle on yard karts and DIY frames, with a 1/4-inch keyway.
Racing rear hubs come with 6 mm or 8 mm keyways, and they are not interchangeable: a hub cut for a 6 mm key will not go onto an axle cut for 8 mm. Front wheels carry their own bearings and slide onto the spindle, so the bearing bore has to match the spindle diameter. On yard karts that is commonly 5/8 or 3/4 inch.
Tire pressure ranges from the makers
Kart racing slicks run about 11 to 16 psi measured hot, far lower than any yard tire. MG’s tables put its dry tires at 0.80 to 1.00 bar hot (11.6 to 14.5 psi) and its rental line at 1.10 bar (16 psi). MG’s FAQ suggests starting at 13 to 15 psi hot, dropping to 10 to 13 psi on a heavily rubbered track, and fitting rim safety screws below 13 psi so the tire cannot jump off the rim. The 58 psi (4 bar) maximum in MG’s tables is a structural ceiling for mounting, not a running number.
Yard and off-road tires are the other way round: the molded figure is the maximum, and the kart’s manual gives the running pressure. Carlstar’s 2-ply yard sizes top out between 12 and 20 psi and the 4-ply versions between 24 and 40 psi. Never run above the sidewall figure.
Hot and cold readings differ. Air pressure in a tire rises with temperature, so a tire set to 14.5 psi at 68°F reads about 18.5 psi if the air inside reaches 140°F. That is why racing targets are quoted hot, and why racers set cold pressures a few psi under the target. A gauge check belongs in the per-session checks on any kart.
How tire size changes speed, pull and clearance
Speed per motor rpm changes in direct proportion to the real tire diameter, and wheel thrust changes by the inverse. The formula is simple: mph = axle rpm x tire diameter in inches x 0.002975.
A worked example with Carlstar’s mounted diameters, going from a 13x5.00-6 Super Lug (13.08 inches) to a 15x6.00-6 Turf Saver (14.32 inches), a ratio of 1.095:
- Speed. A kart geared 6:1 (a 10-tooth motor sprocket on a 60-tooth axle sprocket) with the motor at 4,000 rpm turns the axle at 667 rpm. That is 25.9 mph on the 13s and 28.4 mph on the 15s. The printed sizes, 15 over 13, would predict a 15 percent gain; the real gain is 9.5 percent.
- Pull. Thrust at the ground drops by the same ratio, about 9 percent less for the same motor torque. A kart that was already marginal on a hill or with a heavy rider can end up slower, because the motor never reaches the rpm the math assumes.
- Clearance. The axle rises by half the diameter difference, 0.62 inches here. Going from a 16x6.50-8 (16.25 inches) to an 18x9.50-8 (17.76 inches) adds 0.76 inches of height, plus almost 3 inches of width that needs a 7-inch rim and room under the fenders.
- Re-gearing. To keep the original speed and pull, multiply the gear ratio by the diameter ratio: 6 x 1.095 = 6.57:1. A 66-tooth axle sprocket (6.6:1) lands within about 0.1 mph of the original.
On an electric kart, a taller tire means the motor needs more torque, and so more current, for the same launch, which is worth checking against the controller’s current limit. Swapping our cars from the stock 8-inch set to the 10-inch set changes gearing and stance in the same way, which is why the 8s stay the drift setup.
How to measure the tire you already have
Inflate the tire, read its code, then measure outward from the tread to the axle; it takes ten minutes with a cloth tape and calipers and settles any doubt about worn or unmarked tires.
- Read the sidewall. Note the size code, ply rating, TL or TT, and any compound marking.
- Inflate to your running pressure, since diameter changes with pressure.
- Measure the circumference around the center of the tread and divide by 3.1416. A new MG 11 x 7.10-5 is about 33.6 inches around, its real 10.7-inch height.
- Measure the width at the widest point of the sidewall.
- Check the rim. Measure its width between the inside faces of the flanges where the bead sits; some sellers quote overall wheel width instead.
- Measure the bolt circle with the multipliers above.
- Caliper the axle and spindle, and the keyway width.
Worn tires measure small, so size a replacement for a part-worn tire from the code, not the tape.
Drift karts and caster ride-ons
Drift machines and caster carts are where a size code stops telling the whole story. An open-frame drift kart slides on hard polymer sleeves fitted over its rear wheels, so the sleeve must match the rear wheel diameter and grip it tightly; compound and wear are covered in how slide sleeves work. Crazy Cart style ride-ons slide on urethane rear casters: Razor lists the Crazy Cart XL with an 8 x 2 inch pneumatic front tire and caster rears, so the front is the only tire you buy by size.
Our mini drift cars ship on complete wheels instead. The 8-inch drift setup is stock on every model in the electric line, from the RX7-Style at $5,995, and the 10-inch set is the option for stance. Both are sold as complete fitted sets of four, $249 for the 8s and $449 for the 10s at the time of writing (October 2026). Owners of the gas line should confirm fitment with us before ordering wheels.
What to check before buying replacement tires
Most wrong orders come from matching the size code and nothing else. Run through this list first:
- Rim diameter matches the last number exactly, and rim width matches the maker’s figure for that tire.
- Real mounted diameter, not only the nominal size, if top speed matters.
- Pairs on a solid axle. A live axle has no differential, so rear tires of different diameters scrub. Replace them together.
- Ply and load rating against kart plus rider: a 2-ply 13x5.00-6 carries 290 lb per tire.
- Tube or tubeless, and whether the rim is a split rim that needs a tube.
- Class rules for racing: spec-tire classes name one tire and compound.
- Clearance to frame, fenders and chain for anything wider than stock.
Spare wheels, batteries and guards for our cars are listed on the parts page, with prices shown up front.