🏁 Tire Speed Calculator
🔧 tire speed calculator — global standards (ISO, DOT, ETRTO, JATMA)
The tire speed calculator determines the safe maximum operational speed based on your tire’s speed rating, load index, actual load, ambient temperature, and inflation pressure. Worldwide safety guidelines (USA, EU, Asia) recommend factoring in heat build‑up, load percentage, and under‑inflation. Below you get real‑time derated maximum speed, helping prevent blowouts and ensuring compliance with UN ECE R30 / FMVSS 119 standards.
The tire speed calculator determines the safe maximum operational speed based on your tire’s speed rating, load index, actual load, ambient temperature, and inflation pressure. Worldwide safety guidelines (USA, EU, Asia) recommend factoring in heat build‑up, load percentage, and under‑inflation. Below you get real‑time derated maximum speed, helping prevent blowouts and ensuring compliance with UN ECE R30 / FMVSS 119 standards.
Max load: — kg (— lbs)
kg
lbs
Load percentage: 0%
°C
°F
60%
100%
120%
✅ SAFE MAXIMUM SPEED (derated)
— mph | — km/h
⚡ International note: Speed rating baseline (max speed under ideal load/temp). Actual safe speed may be lower due to load, heat, inflation. USA, EU, Japan all adopt similar derating principles.
📊 Speed ratings & selected rating baseline (mph)
📘 Factor insights (USA / global standards)
🏷️ Speed rating → tire’s max thermal limit
⚖️ Load index → max load capacity at reference pressure
🌡️ >35°C reduces speed by ~1% per 2°C
📦 Load >85% → speed derating 2% per 5% overload
💨 Pressure <90% → rolling resistance & heat ↑
🇺🇸 US DOT recommends never exceeding tire speed rating. Load inflation tables (TRA) adjust maximum speed for heavy loads. Our algorithm applies conservative derating widely accepted in fleet management.