A Mercedes tire size like 225/50R17 decodes as: section width 225 mm, aspect ratio 50 (sidewall = 50% of 225 mm = 112.5 mm = 4.43 in), on a 17-inch rim — giving an overall diameter of 17 + 2×4.43 = 25.87 inches. Mercedes 4MATIC all-wheel-drive models require front and rear tires within ±1% overall diameter of each other. Most Mercedes models use a 5×112 bolt pattern with 66.5 mm centre bore — the G-Class (W463A) is the only exception at 5×130. MOE tires are run-flat capable (80 km lightly loaded at max 80 km/h); MO tires are standard; MO1 is AMG-specific. Typical Mercedes tire pressure: C-Class 35–36 psi (241–248 kPa), E-Class 36–40 psi (248–276 kPa), EQS 42–44 psi (289–303 kPa).
Mercedes Tire Size Calculator
Decode any tire size, compare with 4MATIC safety check, look up OEM fitment for every C-Class / E-Class / S-Class / GLC / GLE / GLS / EQS generation, understand MO/MOE/MO1 markings, check bolt patterns, and get tire pressure in PSI, kPa, or bar.
QUICK EXAMPLE
A W206 C 300 4MATIC leaves Stuttgart on 225/50R17 tires (OD: 25.87") with MOE run-flat marking — no spare wheel in the boot. An owner wants to upgrade to 245/45R18 for a sportier stance: OD rises to 26.65", a 3.01% increase — acceptable for RWD but right at the 4MATIC ±1% limit (actual delta: 3.01% — exceeds safe AWD tolerance). The correct move for 4MATIC is 235/45R18 (OD: 26.34", delta: +1.82%) or staying square on 225/45R18 (OD: 25.98", delta: +0.43%). Use the Compare tab to check any proposed swap before purchasing — the 4MATIC badge fires automatically when the delta exceeds 1%.
Decode Any Mercedes Tire Size
How to Use This Calculator
- 1Tab 1 — Decode Size: Enter any Mercedes tire code (e.g. 225/50R17, 245/45ZR18) or click a preset button. Click Decode to see overall diameter in inches and mm, sidewall height, circumference, revs/mile, revs/km, a proportional SVG profile, and the full worked formula using your exact values.
- 2Tab 2 — Compare Two: Enter Size A (current/OEM) and Size B (proposed replacement). The calculator shows a side-by-side SVG visual, a full dimension delta table, a 4MATIC safety badge (green if ±1% OD, red if exceeded), the general ±3% fitment status badge, and a 7-speed speedometer correction table from 30–120 mph.
- 3Tab 3 — OEM Lookup: Filter by model (C-Class, GLE, EQS, etc.) or search by generation code, year, or tire size. The table shows front/rear OEM sizes, staggered flag, MO/MOE/MO1 rating, PSI, kPa, bolt pattern, and fitment notes for all 21 Mercedes model configurations.
- 4Tab 4 — MO / MOE Guide: Review all four Mercedes OE tire markings (MO, MOE, MO1, Standard) with run-flat capability, maximum flat distance/speed, which models use each, and the critical replacement rules — including when you cannot substitute non-run-flat tires.
- 5Tab 5 — Bolt Pattern: Check the bolt pattern, centre bore, ET offset range, and lug bolt torque for every current Mercedes model. The G-Class 5×130 exception is prominently flagged. The offset guide explains OEM/Flush through Aggressive Poke in four tiers.
- 6Tab 6 — Tire Pressure: Toggle between PSI, kPa, and bar. The table shows front/rear pressure for 12 model/wheel-size combinations. Step-by-step guides show how to change the pressure unit display on both the instrument cluster and the Mercedes Me app.
Mercedes OEM Tire Sizes — All Major Models
| Model | Years | Front OEM | Rear OEM | Front OD" | Rear OD" | MO Rating | Note |
|---|---|---|---|---|---|---|---|
| C-Class W204 | 2008–2014 | 205/55R16 | 205/55R16 | 24.88" | 24.88" | MO | Base; 18" opt staggered |
| C-Class W205 | 2015–2021 | 225/50R17 | 225/50R17 | 25.87" | 25.87" | MOE | Run-flat std |
| C-Class AMG W205 | 2016–2021 | 225/40R18 | 255/35R18 | 25.98" | 25.05" | MO1 | Staggered |
| C-Class W206 | 2022–2025 | 225/50R17 | 225/50R17 | 25.87" | 25.87" | MOE | 19" opt available |
| E-Class W212 | 2010–2016 | 225/55R17 | 225/55R17 | 26.75" | 26.75" | MO | Higher rear PSI |
| E-Class W213 | 2017–2023 | 245/45R18 | 245/45R18 | 26.65" | 26.65" | MOE | 19" opt available |
| E-Class AMG E63 | 2018–2023 | 255/35R20 | 285/30R20 | 27.01" | 26.77" | MO1 | Staggered mandatory |
| S-Class W222 | 2014–2020 | 245/50R18 | 245/50R18 | 27.68" | 27.68" | MOE | 20" opt |
| S-Class W223 | 2021–2025 | 255/45R19 | 285/40R19 | 27.99" | 27.74" | MOE | Air suspension std |
| GLC X253 | 2016–2022 | 235/55R18 | 235/55R18 | 27.99" | 27.99" | MO | 19" opt |
| GLC X254 | 2023–2025 | 235/55R18 | 235/55R18 | 27.99" | 27.99" | MOE | PHEV std |
| GLE W166 | 2016–2019 | 265/45R20 | 265/45R20 | 28.37" | 28.37" | MO | 18" base opt |
| GLE W167 | 2020–2025 | 265/50R19 | 265/50R19 | 28.35" | 28.35" | MOE | 4MATIC ±1% rule |
| GLS X167 | 2020–2025 | 275/50R20 | 275/50R20 | 29.13" | 29.13" | MO | 22" opt |
| A-Class W177 | 2019–2025 | 205/60R16 | 205/60R16 | 25.69" | 25.69" | MO | 18" opt |
| EQS V297 | 2022–2025 | 265/40R21 | 295/35R21 | 28.57" | 28.54" | MOE | No spare — RFT mandatory |
| EQE V295 | 2023–2025 | 235/45R20 | 255/40R20 | 27.99" | 27.57" | MOE | No spare |
| G-Class W463A | 2019–2025 | 265/60R18 | 265/60R18 | 30.47" | 30.47" | MO | ⚠ 5×130 bolt — NOT 5×112 |
OD values computed from ISO metric size formula. Actual manufactured dimensions may vary ±2% by brand and compound. Always verify against your door jamb sticker before purchasing. Data reflects 2023–2026 model years.
Common Mercedes Tire Sizes — Full Dimensions
| Size | OD (in) | OD (mm) | Sidewall (in) | Circumference (in) | Revs/mile | Typical Use |
|---|---|---|---|---|---|---|
| 205/55R16 | 24.88 | 631.9 | 4.44 | 78.17 | 811 | C-Class W204 base; A-Class |
| 225/50R17 | 25.87 | 657.1 | 4.43 | 81.27 | 780 | C-Class W205/W206 OEM |
| 225/45R18 | 25.98 | 659.9 | 3.98 | 81.62 | 776 | C-Class 18" upgrade square |
| 245/45R18 | 26.65 | 676.9 | 4.33 | 83.73 | 757 | E-Class W213 OEM |
| 235/55R18 | 27.99 | 710.9 | 4.99 | 87.92 | 721 | GLC X253/X254 OEM |
| 265/50R19 | 28.35 | 720.0 | 5.22 | 89.04 | 712 | GLE W167 OEM |
| 255/45R19 | 27.99 | 710.9 | 4.52 | 87.92 | 721 | S-Class W223 front |
| 285/40R19 | 27.74 | 704.6 | 4.49 | 87.13 | 728 | S-Class W223 rear staggered |
| 265/45R20 | 28.37 | 720.5 | 4.69 | 89.11 | 711 | GLE W166 OEM |
| 275/50R20 | 29.13 | 740.0 | 5.41 | 91.50 | 693 | GLS X167 OEM |
| 265/40R21 | 28.57 | 725.6 | 4.17 | 89.74 | 706 | EQS V297 front |
| 295/35R21 | 28.54 | 724.8 | 4.06 | 89.65 | 707 | EQS V297 rear staggered |
| 255/35R20 | 27.01 | 686.0 | 3.55 | 84.84 | 747 | AMG E63 / C63 front |
| 265/60R18 | 30.47 | 773.9 | 6.24 | 95.71 | 662 | G-Class W463A OEM |
All values computed from ISO metric size formula. Circumference = OD × π. Revs/mile = 63,360 ÷ circumference (in). Standard inflation assumed. Verify against manufacturer published dimensions for precision applications.
Mercedes Tire Pressure by Model — PSI & kPa
| Model / Wheel Size | Front PSI | Rear PSI | Front kPa | Rear kPa | Notes |
|---|---|---|---|---|---|
| C-Class (17" / 18") | 35–36 | 35–36 | 241–248 | 241–248 | MOE run-flat std; check door jamb |
| C-Class AMG C43/C63 | 38 | 38 | 262 | 262 | MO1 compound; higher inflation |
| E-Class W213 (18") | 36 | 38 | 248 | 262 | Higher rear for load; verify placard |
| S-Class W223 (19") | 38 | 40 | 262 | 276 | Air suspension; adjust for payload |
| GLC X254 (18") | 36 | 36 | 248 | 248 | PHEV battery weight factored in |
| GLE W167 (19") | 36 | 38 | 248 | 262 | 4MATIC; higher rear load spec |
| GLS X167 (20") | 38 | 40 | 262 | 276 | Full-size SUV; 7-seat load PSI |
| EQS V297 (21") | 42 | 44 | 289 | 303 | EV — higher PSI for range & weight |
| EQE V295 (20") | 40 | 42 | 276 | 289 | EV — no spare; RFT mandatory |
| G-Class W463A (18") | 36 | 38 | 248 | 262 | Off-road use: drop to 25–28 psi |
| A-Class W177 (16"/18") | 35 | 35 | 241 | 241 | Base; A35 AMG same spec |
| CLA C118 (18") | 36 | 36 | 248 | 248 | CLA45 AMG: verify AMG placard |
Always check cold pressure (parked 3+ hours). Driving raises pressure 4–6 PSI / 28–41 kPa — never bleed hot pressure down to the cold spec. Your door jamb sticker overrides all charts. Sources: Mercedes-Benz AG owner manuals, carsguide.com.au tyre placard database, tirerack.com OE spec library.
Mercedes Tire Size Formulas & Reference
1. Reading a Mercedes Metric Tire Code (e.g. 245/45R18)
First number → section width in millimetres (245 mm). Second number → aspect ratio, the sidewall height as a percentage of width (45%). R → radial construction. Third number → rim diameter in inches (18").
2. Overall Diameter (OD) from Metric Code
Sidewall (mm) = Width × (Aspect ÷ 100) Sidewall (in) = Sidewall (mm) ÷ 25.4 OD = Rim (in) + 2 × Sidewall (in)
Example — 225/50R17 (C-Class W205/W206 OEM): sidewall = 225 × 0.50 = 112.5 mm = 4.43". OD = 17 + 2 × 4.43 = 25.87" (657.1 mm).
3. Circumference
C = OD × π
225/50R17 example: C = 25.87 × 3.14159 = 81.27" (2,064.3 mm).
4. Revolutions per Mile
Rev/mile = 63,360 ÷ C (in)
225/50R17 example: 63,360 ÷ 81.27 = 780 rev/mi.
5. Revolutions per Kilometre
Rev/km = 1,000,000 ÷ C (mm)
225/50R17 example: 1,000,000 ÷ 2,064.3 = 485 rev/km.
6. OD Delta % (comparing two sizes)
Δ% = (New OD − Old OD) ÷ Old OD × 100
Example: replacing 225/50R17 (25.87") with 245/45R18 (26.65") gives Δ% = (26.65 − 25.87) ÷ 25.87 × 100 = +3.01%.
7. Mercedes 4MATIC Safe-Swap Threshold
±1.0% OD difference is safe for 4MATIC AWD systems. ±1.0–3.0% calls for caution — check with a dealer. Above ±3.0% risks transfer case or ESP damage. (The general passenger-car limit is ±3%; 4MATIC tightens this to ±1%.)
8. Speedometer Correction
True speed = Indicated speed × (New OD ÷ Old OD)
Example: 100 km/h indicated, swapping 225/50R17 → 245/45R18: true speed = 100 × (26.65 ÷ 25.87) = 103.0 km/h — the speedo reads about 3% low, a ticket risk above 97 km/h indicated.
9. Staggered Fitment — OD Matching Rule
For models like the S-Class W223 (255/45R19 front / 285/40R19 rear): front OD = 27.99", rear OD = 27.74", a delta of 0.25" (0.90%) — within the 4MATIC ±1% limit.
10. MO / MOE Flat-Distance Formula
MOE tires, lightly loaded: up to 80 km at ≤80 km/h after pressure loss. MOE tires, fully loaded: up to 30 km at ≤80 km/h. Non-MOE (MO / Standard): 0 km — a puncture means stopping immediately.
11. Tire Pressure Conversion
PSI → kPa: × 6.895 kPa → PSI: × 0.14504 PSI → bar: × 0.06895 bar → PSI: × 14.504
Examples: 35 PSI = 241 kPa. 248 kPa = 36 PSI. 36 PSI = 2.48 bar. 2.5 bar = 36.3 PSI.
How to Read a Mercedes Tire Size
Every Mercedes tire sidewall carries a three-part metric code — for example, 245/45R18 on the E-Class W213. The first number (245) is the section width in millimetres. The second (45) is the aspect ratio: the sidewall height is 45% of 245 mm = 110.25 mm = 4.34 inches. The R denotes radial construction, and 18 is the rim diameter in inches. Overall diameter is therefore 18 + 2 × 4.34 = 26.68 inches. This mixed metric/imperial system is a legacy of 1960s standardisation — the width went metric while rim diameters stayed in inches, and the convention persists across all manufacturers to this day. On the same sidewall you will also find the load index (e.g. 95), speed rating (e.g. Y), and the Mercedes OE marking (MO, MOE, or MO1) if applicable.
MO vs MOE vs MO1 — Why the Marking Matters More Than the Size
Most Mercedes owners focus on the size code and ignore the OE marking — a mistake that can leave you stranded. MO (Mercedes Original) tires are standard construction, optimised for Mercedes suspension geometry and NVH targets, and always paired with a spare wheel. MOE (Mercedes Original Extended) tires have reinforced sidewalls that allow up to 80 km of driving at ≤80 km/h after a complete blowout — critical because MOE-equipped trims ship with no spare wheel. If you replace MOE with standard tires and suffer a puncture, you have zero emergency mobility. MO1 is the AMG designation: tires tuned for the higher lateral acceleration and brake temperatures of AMG models, always in staggered fitments, and not run-flat capable. Fitting MO where MOE is required — or vice versa — is the single most consequential tire mistake a Mercedes owner can make.
The 4MATIC ±1% Rule — Stricter Than You Think
The general automotive guideline allows tire diameter changes of up to ±3% before speedometer error and ADAS calibration become concerns. Mercedes tightens this to ±1% for all 4MATIC models — and for good reason. The 4MATIC system continuously monitors wheel speed differentials to distribute torque. A tire 2–3% larger on one axle registers as a permanent wheel-speed mismatch, forcing the transfer case to work against itself on every straight. Over time this causes premature clutch pack wear (wet-clutch 4MATIC) or differential strain (torque-vectoring 4MATIC). A real example: upgrading a GLE W167 from stock 265/50R19 (OD: 28.35\") to 275/55R19 (OD: 29.33\") is a 3.46% delta — comfortable on a rear-wheel-drive car but a transfer-case stressor on the GLE. The correct upgrade is 275/50R19 (OD: 28.74\", delta: +1.37%) — borderline — or 265/55R19 (OD: 28.98\", delta: +2.22%), which requires dealer approval. Use the Compare tab: the 4MATIC badge fires automatically when the delta exceeds 1%.
Staggered Fitments on Mercedes — What You Cannot Do
Staggered fitments — where front and rear tires are different sizes — appear on the AMG C43, AMG C63, AMG E63, S-Class W223, EQS, EQE, and CLA45 AMG among others. The performance benefit is a wider rear contact patch for traction and stability. The practical constraint: staggered tires cannot be rotated front-to-rear. You can only rotate side-to-side on the same axle if the tires are non-directional — and most Mercedes performance tires are directional, meaning even that is not possible. The result is that rear tires on staggered setups wear faster (driven axle, no rotation) and must be replaced more frequently than fronts. On the S-Class W223 with 255/45R19 front and 285/40R19 rear, the rear tire is approximately 30 mm wider — expect to replace rears every 15,000–20,000 miles versus 25,000–35,000 miles for fronts under normal driving.
G-Class Bolt Pattern Exception — 5×130, Not 5×112
Every current Mercedes model uses a 5×112 bolt pattern with a 66.5 mm centre bore — with one absolute exception. The G-Class W463A (2019–2025) uses 5×130 with an 84.1 mm centre bore, inherited from the Puch G-Wagen military origins and maintained through every generation to preserve parts interchangeability for military and expedition operators. A 5×112 wheel physically cannot mount on a G-Class hub, and a G-Class wheel will not bolt onto any other Mercedes. This catches buyers of used G-Class wheels or owners trying to share wheels across a mixed-fleet garage. Lug bolt torque for the G-Class is also slightly higher at 160–180 Nm (118–133 ft-lb) versus the 130–160 Nm (96–118 ft-lb) standard across all other Mercedes models. If you are shopping aftermarket wheels for a G-Class, confirm the 5×130 / 84.1 mm spec explicitly — most wheel retailers default to 5×112 when you search "Mercedes" without specifying the G-Class.
Mercedes EV Tire Pressure — Why It Is Higher Than Petrol Models
The EQS V297, EQE V295, and EQB X243 run noticeably higher tire pressures than equivalent petrol or diesel Mercedes models. The EQS specifies 42 psi (289 kPa) front and 44 psi (303 kPa) rear — roughly 6–8 psi higher than a comparable S-Class W223. There are two engineering reasons. First, battery weight: the EQS weighs approximately 2,480 kg (5,467 lb) — nearly 500 kg more than a W223 S-Class — requiring higher inflation to support the additional load without excessive sidewall deflection. Second, rolling resistance: every 1 psi of under-inflation increases rolling resistance by approximately 0.3%, translating to around 1.5–2% range loss on a 200-mile (320 km) charge. Mercedes engineers the higher EV tire pressure to recover this range penalty. The practical implication: never normalise EQS or EQE pressure to petrol-model specs. An EQS running at C-Class pressure (35 psi) is both under-inflated for its kerb weight and sacrificing approximately 10–15 miles of range per charge. Check pressure monthly — EV tires lose pressure at the same rate as conventional tires (approximately 1–2 psi per month at ambient temperature).
MO / MOE Marking Quick Reference
| Marking | Full Name | Run-Flat | Max Flat Distance | Max Flat Speed | Typical Models |
|---|---|---|---|---|---|
| MO | Mercedes Original | No | N/A — stop immediately | N/A | C-Class W204, E-Class W212, GLC X253, GLE W166, G-Class, A-Class W177 |
| MOE | Mercedes Original Extended | Yes | 80 km light / 30 km full load | ≤80 km/h (50 mph) | C-Class W205/W206, E-Class W213, S-Class W222/W223, GLC X254, GLE W167, EQS, EQE |
| MO1 | Mercedes Original AMG | No | N/A — stop immediately | N/A | AMG C43, AMG C63 W205, AMG E53, AMG E63 W213, AMG GT |
| — | No OE Marking | No | N/A | N/A | Some older models; aftermarket replacements |
If your Mercedes shipped with MOE tires and no spare wheel, replacing with non-run-flat tires is only safe if you simultaneously add a tyre repair kit. Sources: Bridgestone MOE technical bulletin, TireRack MOExtended guide, Goodyear OE marking reference.
Mercedes Bolt Pattern Quick Reference
| Model Group | Bolt Pattern | Centre Bore | Lug Bolt | Torque (Nm) | Torque (ft-lb) |
|---|---|---|---|---|---|
| A / B / CLA / GLA / GLB | 5×112 | 66.5 mm | M14×1.5 | 130–160 | 96–118 |
| C-Class (all generations) | 5×112 | 66.5 mm | M14×1.5 | 130–160 | 96–118 |
| E-Class (all generations) | 5×112 | 66.5 mm | M14×1.5 | 130–160 | 96–118 |
| S-Class (all generations) | 5×112 | 66.5 mm | M14×1.5 | 130–160 | 96–118 |
| GLC / GLE / GLS | 5×112 | 66.5 mm | M14×1.5 | 130–160 | 96–118 |
| EQS / EQE / EQB / EQA | 5×112 | 66.5 mm | M14×1.5 | 130–160 | 96–118 |
| AMG GT / SL / SLS | 5×112 | 66.5 mm | M14×1.5 | 130–160 | 96–118 |
| G-Class W463A ⚠ EXCEPTION | 5×130 | 84.1 mm | M14×1.5 | 160–180 | 118–133 |
Always torque in a star pattern. Re-torque after 50–100 km following any wheel change. Use only OEM-style ball-seat lug bolts — Mercedes does not use tapered-seat lug nuts. G-Class 5×130 wheels are physically incompatible with all other Mercedes models.
4MATIC Tire Size Warning — Read Before Upgrading
All Mercedes 4MATIC all-wheel-drive models require front and rear tire overall diameters to remain within ±1% of each other. This is stricter than the general ±3% passenger-car guideline. Exceeding this limit causes:
- →Permanent wheel-speed mismatch — the AWD system fights itself on every straight
- →Premature transfer case and centre differential wear
- →ESP / ABS calibration errors — reduced emergency braking performance
- →Potential transmission warning lights and limp-home mode activation
- →Voided powertrain warranty on vehicles under manufacturer cover
Use the Compare tab above — the 4MATIC safety badge fires automatically when the OD delta exceeds 1%. Always verify with your Mercedes-Benz dealer before fitting a non-OEM tire size on a 4MATIC model.
Frequently Asked Questions
Disclaimer:All OEM tire sizes, pressures, bolt patterns, MO/MOE specifications, and torque values are provided for reference only and sourced from publicly available manufacturer documentation and community-verified data. Always verify against your vehicle's door jamb sticker, owner's manual, or an authorised Mercedes-Benz dealer before purchasing replacement tires or wheels. Tire fitment can vary by trim level, production date, and regional market. tirecalculatorhub.com is not affiliated with Mercedes-Benz AG or Daimler Truck AG.