PT1000 Temperature ↔ Resistance Calculator
Convert between temperature (°C) and resistance (Ω) for platinum RTD sensors using standard Callendar–Van Dusen coefficients.
Valid reference range for this calculator: -200°C to 850°C.
What is a PT1000 sensor?
A PT1000 is a platinum resistance temperature detector (RTD) with a nominal resistance of 1000 Ω at 0°C. As temperature rises, resistance increases in a predictable, highly repeatable way. PT1000 elements are popular in HVAC, industrial automation, lab instrumentation, food processing, and energy systems because they offer excellent stability and accuracy over a wide range.
How this PT1000 calculator works
This tool uses the Callendar–Van Dusen model, the standard mathematical relationship between platinum RTD resistance and temperature.
For T ≥ 0°C: R(T) = R₀ × [1 + A·T + B·T²]
For T < 0°C: R(T) = R₀ × [1 + A·T + B·T² + C·(T − 100)·T³]
Where:
- R(T) is sensor resistance at temperature T
- R₀ is nominal resistance at 0°C (1000 Ω for PT1000)
- A, B, C are standard coefficients (chosen by RTD curve type)
Typical IEC 60751 PT1000 reference values
| Temperature (°C) | Approx. Resistance (Ω) |
|---|---|
| -50 | 803.06 |
| 0 | 1000.00 |
| 25 | 1097.35 |
| 100 | 1385.06 |
| 200 | 1758.56 |
| 400 | 2470.92 |
| 850 | 3904.81 |
How to use the calculator
1) Pick a mode
Select either Temperature → Resistance or Resistance → Temperature.
2) Choose coefficient standard
Most modern sensors use IEC 60751 (α = 0.00385). Use α = 0.00392 only if your sensor datasheet explicitly calls for it.
3) Confirm R₀
For a PT1000 element, R₀ is usually 1000 Ω. Some transmitters or custom probes may use a different nominal value; if so, enter it directly.
4) Calculate and interpret
The result appears immediately, with units and selected standard noted for traceability.
PT1000 vs PT100: quick comparison
- PT1000: 1000 Ω at 0°C, larger signal change in ohms, often less sensitive to lead-wire resistance in simple two-wire setups.
- PT100: 100 Ω at 0°C, extremely common in industry, often paired with 3-wire/4-wire compensation methods.
- Both offer excellent linearity and long-term stability compared with many thermistors and some thermocouples in moderate ranges.
Accuracy tips for real installations
Wiring method matters
Two-wire connections add lead resistance directly to the reading. For tighter accuracy, use 3-wire or 4-wire measurement where possible.
Use the right curve type
A mismatch between sensor curve and instrument configuration (for example, using α = 0.00385 sensor with α = 0.00392 math) can create significant temperature errors.
Avoid self-heating and noise
Measurement current that is too high can warm the sensing element. Keep current low and use good shielding/grounding practices for long cable runs.
FAQ
What temperature range is supported?
This calculator is intended for the standard platinum RTD range of -200°C to 850°C.
Can I use this for PT100?
Yes. Set R₀ = 100 and keep the correct coefficient standard for your sensor.
Why doesn’t inverse conversion use a simple formula?
For negative temperatures, the RTD equation includes a cubic term, so this calculator uses a robust numerical solve method to get temperature from resistance.