Thermocouple Tolerance Classes
Complete limits of error for all thermocouple types — Standard and Special tolerance classes, positive and negative temperature ranges. Per ASTM E230, E1751, E696 and IEC 60584-2.
Tolerance CalculatorHow to Apply Tolerance Limits
For each tolerance range, the applicable limit is whichever value is greater — the fixed °C limit or the percentage of measured temperature. Example: Type K Standard at 500°C: Fixed = ±2.2°C; Percentage = 500 × 0.0075 = ±3.75°C. Since ±3.75 > ±2.2, the percentage limit applies: ±3.75°C. Use the Tolerance Calculator to compute this automatically for any type and temperature.
Complete Tolerance Table — All Types, All Ranges
| Type | Tolerance Class | Temperature Range | Fixed Limit | % Limit | IEC Class | Standard |
|---|---|---|---|---|---|---|
| J | Standard | 0 to +750°C | ±2.2°C | ±0.75% | Class 2 | E230 |
| Special | 0 to +750°C | ±1.1°C | ±0.4% | Class 1 | E230 | |
| Standard | −40 to 0°C | ±2.2°C | ±2.0% | Class 2 | E230 | |
| K | Standard | 0 to +1260°C | ±2.2°C | ±0.75% | Class 2 | E230 |
| Special | 0 to +1260°C | ±1.1°C | ±0.4% | Class 1 | E230 | |
| Standard | −200 to 0°C | ±2.2°C | ±2.0% | Class 2 | E230 | |
| T | Standard | 0 to +370°C | ±1.0°C | ±0.75% | Class 2 | E230 |
| Special | 0 to +370°C | ±0.5°C | ±0.4% | Class 1 | E230 | |
| Standard | −200 to 0°C | ±1.0°C | ±1.5% | Class 2 | E230 | |
| Special | −200 to 0°C | ±0.5°C | ±0.8% | Class 1 | E230 | |
| E | Standard | 0 to +870°C | ±1.7°C | ±0.5% | Class 2 | E230 |
| Special | 0 to +870°C | ±1.0°C | ±0.4% | Class 1 | E230 | |
| Standard | −200 to 0°C | ±1.7°C | ±1.0% | Class 2 | E230 | |
| Special | −200 to 0°C | ±1.0°C | ±0.5% | Class 1 | E230 | |
| N | Standard | 0 to +1260°C | ±2.2°C | ±0.75% | Class 2 | E230 |
| Special | 0 to +1260°C | ±1.1°C | ±0.4% | Class 1 | E230 | |
| R | Standard | 0 to +1480°C | ±1.5°C | ±0.25% | Class 2 | E1751 |
| Special | 0 to +1480°C | ±0.6°C | ±0.1% | Class 1 | E1751 | |
| S | Standard | 0 to +1480°C | ±1.5°C | ±0.25% | Class 2 | E1751 |
| Special | 0 to +1480°C | ±0.6°C | ±0.1% | Class 1 | E1751 | |
| B | Standard | +600 to +1700°C | N/A | ±0.5% | Class 2 | E1751 |
| Special | +600 to +1700°C | N/A | ±0.25% | Class 1 | E1751 | |
| C | Standard | 0 to +2315°C | ±4.5°C | ±1.0% | — | E696 |
| Special | 0 to +2315°C | ±2.3°C | ±0.5% | — | E696 |
All limits apply as whichever value (°C or %) is greater at the measured temperature, except Type B which is percentage only. IEC 60584-2 Class 3 (extended sub-zero) for Types K, N, T, E below −200°C not shown — consult IEC 60584-2 directly for those ranges.