PT100 Resistance Table: Full Chart -200 to 850 °C (IEC 60751)

Updated 15 October 2026: completed the table to every 1 °C up to 850 °C, added a °F table, corrected the slope column and the legacy-curve error figures. Reviewed by the Focusens Engineering Team.

What the numbers mean

A PT100 is a platinum resistance temperature detector with nominal resistance R0 = 100.00 Ω at 0 °C. Its temperature coefficient α = (R100 - R0) / (100 °C × R0) is 0.00385 °C⁻¹. IEC 60751 writes it as 3.851 × 10⁻³ °C⁻¹, and the equation coefficients give 0.00385055. The same chart on the 1000 Ω base is the PT1000 resistance table. Every PT100 follows the same normalized platinum curve as a PT1000, scaled by a factor of 10.

Reference point	PT100	PT1000	Local slope, PT100
-200 °C (lower limit)	18.52 Ω	185.20 Ω	0.432 Ω/°C
0 °C (ice point)	100.00 Ω	1000.00 Ω	0.391 Ω/°C
25 °C (room)	109.73 Ω	1097.35 Ω	0.388 Ω/°C
100 °C (steam point)	138.51 Ω	1385.06 Ω	0.379 Ω/°C
200 °C	175.86 Ω	1758.56 Ω	0.368 Ω/°C
850 °C (upper limit)	390.48 Ω	3904.81 Ω	0.293 Ω/°C

Datasheets mix two slope figures. 0.385 Ω/°C is the average from 0 to 100 °C, which is how α = 0.00385 is defined. 0.391 Ω/°C is the slope at 0 °C, and it falls to 0.293 Ω/°C at 850 °C. To turn a small resistance error into degrees, such as cable resistance, divide by the local slope: 1 Ω of loop resistance is 2.56 °C at 0 °C and 2.64 °C at 100 °C.

Complete PT100 resistance table

The tables cover every 1 °C across the standardized range from -200 to 850 °C, rounded to 0.01 Ω. Read the row for the tens and the column for the units: row 120, column 6 is 126 °C, which reads 148.33 Ω. In the negative table, row -120, column -6 is -126 °C.

Negative range, -200 to -1 °C

Positive range, 0 to 850 °C

PT100 table in °F

Rows step by 50 °F and columns add 0 to 40 °F, so row 200, column +20 is 220 °F. The range ends at -328 °F and 1562 °F, which are -200 and 850 °C. For an exact 1 °F value, convert with (°F - 32) × 5/9 and use the °C table.

Download the full 1 °C step PT100 table (CSV, 1051 rows, -200 to 850 °C)

The equations behind the table

The standard resistance-temperature curve of platinum RTDs is specified by the Callendar-Van Dusen equation per IEC 60751:

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]

Standard European curve (α = 0.00385) vs legacy curves

The table above uses α = 0.00385 °C⁻¹, the curve adopted by IEC 60751, DIN EN 60751, and ASTM E1137. Legacy American (α = 0.00392) or Japanese (JIS C1604, α = 0.003916) sensors have higher resistance at 100 °C (139.16 to 139.20 Ω). Read through an α = 0.00385 table, an α = 0.003916 element reads high by about 1.7 °C at 100 °C, 3.5 °C at 200 °C and 5.3 °C at 300 °C (our calculation from the JIS C 1604-1981 coefficients). JIS C 1604 adopted the IEC curve in its 1989 revision, so a JPt100 mostly turns up in old instruments and old spare parts.

IEC 60751 tolerance classes for PT100

IEC 60751 gives four tolerance classes for complete thermometers, and each class has a range of validity that depends on whether the probe uses a film or a wire-wound element:

Class	Tolerance formula (±°C)	Valid range, film (F)	Valid range, wire-wound (W)	Error @ 0 °C	Error @ 100 °C
Class AA	0.10 + 0.0017×|t|	0 to 150 °C	-50 to 250 °C	±0.10 °C (±0.039 Ω)	±0.27 °C (±0.102 Ω)
Class A	0.15 + 0.0020×|t|	-30 to 300 °C	-100 to 450 °C	±0.15 °C (±0.059 Ω)	±0.35 °C (±0.133 Ω)
Class B	0.30 + 0.0050×|t|	-50 to 500 °C	-196 to 600 °C	±0.30 °C (±0.117 Ω)	±0.80 °C (±0.303 Ω)
Class C	0.60 + 0.0100×|t|	-50 to 600 °C	-196 to 600 °C	±0.60 °C (±0.234 Ω)	±1.60 °C (±0.607 Ω)

Bare elements have their own grades in the 2022 edition, F 0.1 to F 0.6 and W 0.1 to W 0.6, with the same formulas. The film ranges match the table above; two wire-wound ranges are wider (W 0.1 from -100 to 350 °C, W 0.3 and W 0.6 from -196 to 660 °C).

The class covers the element as shipped. Drift in service, the instrument input and the cable come on top, so a class A element on a long 2-wire run can still read several degrees off.

PT100 or PT1000: same curve, different error budget

PT100 and PT1000 share the same normalized curve shape. Because a PT100's resistance is 10 times lower, its average sensitivity is 0.385 Ω/°C against 3.85 Ω/°C for a PT1000, and the same cable costs it ten times the error. With 30 m of 24 AWG copper each way (about 5.05 Ω of loop resistance), at 0 °C:

When you should still specify PT100

Specify a PT100 when the input card accepts only PT100, which is common on older PLC and DCS analog cards, or when the input drives a fixed 1 mA: at that current a PT100 dissipates 0.1 mW and a PT1000 1.0 mW (P = I²R).

Element construction: thin film, ceramic and glass

Construction	Temperature range	Vibration resistance	Best suited for
Thin-film	-50 to 500 °C for class B (check the element datasheet for its upper limit)	High	HVAC, automotive, high-volume OEM probes
Glass wire-wound	-200 to 400 °C (typical)	Moderate	Cryogenic applications, chemical immersion
Ceramic wire-wound	-200 to 850 °C	Moderate	High-temperature process probes up to 850 °C

Can a PT100 run on a PT1000 transmitter?

No. A transmitter set for PT1000 expects about 1000 Ω at 0 °C and sees about 100 Ω. That is below the bottom of the PT1000 range (185.20 Ω at -200 °C), so the input reports an under-range or short-circuit fault rather than a temperature. Change the input type in the transmitter settings first. The reverse mistake, a PT1000 on a PT100 input, reads as over-range or open circuit. Above about 225 °C the fault disappears and the input shows a false reading inside its range; see the FAQ below.

FAQ

What is the resistance of a PT100 at 0 °C?
Nominally 100.00 Ω. A class A element may differ by up to ±0.06 Ω (±0.15 °C) at 0 °C.

What is the resistance of a PT100 at 100 °C?
138.51 Ω.

Why does my multimeter show 108.5 Ω?
At 22 °C a PT100 reads 108.57 Ω at the element. On a 2-wire probe the leads add their own resistance on top.

What does a PT1000 input show if a PT100 is connected to a hot process?
Above about 225 °C a PT100 reads more than 185.20 Ω, the PT1000 value at -200 °C, so the input stops reporting a fault and shows a false temperature inside its range. A PT100 at 500 °C (280.98 Ω) reads as about -178 °C on a PT1000 input (our calculation from the IEC 60751 table). On ovens and other hot processes, check the input type before power-up instead of relying on a sensor-fault alarm. How the two elements differ in wiring and input support is covered in our PT100 vs PT1000 comparison.

Related pages and Focusens PT100 probes

• Factory customized PT100 probes
• PT100/PT1000 Sensor Probes for Beverage Systems
• PT1000 resistance table
• Contact Focusens application engineers

References

IEC 60751:2022, Industrial platinum resistance thermometers and platinum temperature sensors: IEC Webstore and the iTeh preview of IEC 60751:2022.

JIS C 1604:2013, the Japanese standard for platinum RTDs: Okazaki summary of JIS C 1604:2013.