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Instrumentation reference

RTD Resistance Chart

Look up or convert nominal Pt100, Pt500, and Pt1000 resistance versus temperature using the α ≈ 0.00385 platinum RTD characteristic.

Default
Pt100 at 0°C = 100 Ω
Range
−200°C to 850°C
Basis
IEC 60751:2022 scope

Nominal platinum RTD values

RTD Resistance vs. Temperature Lookup

Use the exact converter for any valid point, then use the server-rendered table for fast reference checkpoints.

The default is Pt100 at 0°C, where the nominal resistance is 100.00 Ω. Values are calculated from the stated Callendar–Van Dusen characteristic rather than copied from a standards table.

Scroll horizontally to view additional resistance columns and vertically to view additional temperatures. Column headers remain visible while scrolling.

Calculated nominal α ≈ 0.00385 platinum RTD resistance-temperature checkpoints from −200°C through 850°C in 10°C increments.
Temperature Nominal resistance
-200 -328 18.52 92.60 185.20
-190 -310 22.83 114.13 228.25
-180 -292 27.10 135.48 270.96
-170 -274 31.34 156.68 313.35
-160 -256 35.54 177.72 355.43
-150 -238 39.72 198.62 397.23
-140 -220 43.88 219.38 438.76
-130 -202 48.00 240.02 480.05
-120 -184 52.11 260.55 521.10
-110 -166 56.19 280.97 561.93
-100 -148 60.26 301.28 602.56
-90 -130 64.30 321.50 643.00
-80 -112 68.33 341.63 683.25
-70 -94 72.33 361.67 723.35
-60 -76 76.33 381.64 763.28
-50 -58 80.31 401.53 803.06
-40 -40 84.27 421.35 842.71
-30 -22 88.22 441.11 882.22
-20 -4 92.16 460.80 921.60
-10 14 96.09 480.43 960.86
0 32 100.00 500.00 1000.00
10 50 103.90 519.51 1039.03
20 68 107.79 538.97 1077.93
30 86 111.67 558.36 1116.73
40 104 115.54 577.70 1155.41
50 122 119.40 596.99 1193.97
60 140 123.24 616.21 1232.42
70 158 127.08 635.38 1270.75
80 176 130.90 654.48 1308.97
90 194 134.71 673.53 1347.07
100 212 138.51 692.53 1385.05
110 230 142.29 711.46 1422.93
120 248 146.07 730.34 1460.68
130 266 149.83 749.16 1498.32
140 284 153.58 767.92 1535.84
150 302 157.33 786.63 1573.25
160 320 161.05 805.27 1610.54
170 338 164.77 823.86 1647.72
180 356 168.48 842.39 1684.78
190 374 172.17 860.86 1721.73
200 392 175.86 879.28 1758.56
210 410 179.53 897.64 1795.28
220 428 183.19 915.94 1831.88
230 446 186.84 934.18 1868.36
240 464 190.47 952.36 1904.73
250 482 194.10 970.49 1940.98
260 500 197.71 988.56 1977.12
270 518 201.31 1006.57 2013.14
280 536 204.90 1024.52 2049.05
290 554 208.48 1042.42 2084.84
300 572 212.05 1060.26 2120.51
310 590 215.61 1078.04 2156.08
320 608 219.15 1095.76 2191.52
330 626 222.68 1113.42 2226.85
340 644 226.21 1131.03 2262.06
350 662 229.72 1148.58 2297.16
360 680 233.21 1166.07 2332.14
370 698 236.70 1183.51 2367.01
380 716 240.18 1200.88 2401.76
390 734 243.64 1218.20 2436.40
400 752 247.09 1235.46 2470.92
410 770 250.53 1252.66 2505.33
420 788 253.96 1269.81 2539.61
430 806 257.38 1286.89 2573.79
440 824 260.78 1303.92 2607.85
450 842 264.18 1320.90 2641.79
460 860 267.56 1337.81 2675.62
470 878 270.93 1354.67 2709.33
480 896 274.29 1371.46 2742.93
490 914 277.64 1388.20 2776.41
500 932 280.98 1404.89 2809.78
510 950 284.30 1421.51 2843.03
520 968 287.62 1438.08 2876.16
530 986 290.92 1454.59 2909.18
540 1004 294.21 1471.04 2942.08
550 1022 297.49 1487.44 2974.87
560 1040 300.75 1503.77 3007.54
570 1058 304.01 1520.05 3040.10
580 1076 307.25 1536.27 3072.54
590 1094 310.49 1552.43 3104.87
600 1112 313.71 1568.54 3137.08
610 1130 316.92 1584.59 3169.18
620 1148 320.12 1600.58 3201.15
630 1166 323.30 1616.51 3233.02
640 1184 326.48 1632.38 3264.77
650 1202 329.64 1648.20 3296.40
660 1220 332.79 1663.96 3327.92
670 1238 335.93 1679.66 3359.32
680 1256 339.06 1695.30 3390.61
690 1274 342.18 1710.89 3421.78
700 1292 345.28 1726.42 3452.84
710 1310 348.38 1741.89 3483.78
720 1328 351.46 1757.30 3514.60
730 1346 354.53 1772.65 3545.31
740 1364 357.59 1787.95 3575.90
750 1382 360.64 1803.19 3606.38
760 1400 363.67 1818.37 3636.74
770 1418 366.70 1833.50 3666.99
780 1436 369.71 1848.56 3697.12
790 1454 372.71 1863.57 3727.14
800 1472 375.70 1878.52 3757.04
810 1490 378.68 1893.41 3786.83
820 1508 381.65 1908.25 3816.49
830 1526 384.60 1923.02 3846.05
840 1544 387.55 1937.74 3875.49
850 1562 390.48 1952.41 3904.81

Calculated nominal values use the published α ≈ 0.00385 Callendar–Van Dusen coefficients stated in the source section. These values are not a calibration certificate or a reproduction of the IEC standard table.

How to Read an RTD Resistance Chart

A platinum RTD changes resistance predictably with temperature. A Pt100 has a nominal resistance of 100 Ω at 0°C, while Pt500 and Pt1000 elements use 500 Ω and 1000 Ω at the same reference temperature.

  1. Select the RTD type that matches the sensor element or transmitter configuration.
  2. For a known temperature, use Temperature → resistance to calculate the nominal resistance. For a measured resistance, switch to Resistance → temperature.
  3. Use the table as a fast checkpoint and the curve to see where the operating point lies across the full characteristic.

Field check: If you are troubleshooting a real sensor, identify whether the circuit is 2-wire, 3-wire, or 4-wire before comparing an ohmmeter reading directly with the nominal table.

Pt100, Pt500, and Pt1000 Resistance Values

The number in the RTD designation is the nominal resistance at 0°C. This page applies the same α ≈ 0.00385 normalized platinum characteristic to three common nominal resistances, so the resistance scale changes while the temperature scale does not.

Pt100
100 Ω nominal at 0°C. Common in industrial process and instrumentation systems.
Pt500
500 Ω nominal at 0°C. The calculated resistance is five times the corresponding Pt100 value before display rounding.
Pt1000
1000 Ω nominal at 0°C. The calculated resistance is ten times the corresponding Pt100 value before display rounding.

Do not use these values for a different platinum characteristic such as α ≈ 0.00392, or for nickel, copper, or thermistor sensors. Those require different equations and reference data.

Callendar–Van Dusen Equation Used by the Chart

The nominal resistance values are generated locally from the published Callendar–Van Dusen form for the α ≈ 0.00385 platinum characteristic. The page uses one canonical temperature unit (°C) and one canonical resistance unit (Ω).

For T ≥ 0°C R(T) = R0[1 + AT + BT2]

Above 0°C, the C term is not used.

For T < 0°C R(T) = R0[1 + AT + BT2 + C(T − 100)T3]

Below 0°C, the additional C term captures the low-temperature curvature.

Coefficients used

  • A3.9083 × 10−3 °C−1
  • B−5.775 × 10−7 °C−2
  • C−4.183 × 10−12 °C−4
  • R0100, 500, or 1000 Ω at 0°C
  • TTemperature in °C, limited here to −200°C through 850°C

For reverse lookup above 0°C, the page uses the bounded quadratic inverse. Below 0°C, it solves the same monotonic equation numerically within the valid range. The page never extrapolates beyond −200°C or 850°C.

Why Measured RTD Resistance May Not Match the Chart

The chart represents the nominal element characteristic. A field resistance measurement includes the sensor plus the measurement circuit, and several effects can move the observed value away from the nominal curve.

Lead resistance

In a 2-wire circuit, lead resistance adds directly to the measured resistance. Three-wire compensation depends on matched leads, while four-wire measurement best removes lead contribution.

Sensor tolerance

An individual element is allowed to deviate from the nominal characteristic within its specified tolerance or calibration behavior.

Self-heating

Excitation current dissipates power in the RTD. If the element cannot reject that heat, its actual temperature can rise above the medium temperature.

Instrument and installation effects

Meter accuracy, contact resistance, connector condition, immersion depth, thermal gradients, and response lag can all affect the observed result.

Worked RTD Lookup Examples

Example 1 — Pt100 at 100°C

Given: Pt100, R0 = 100 Ω, T = 100°C.

Because T ≥ 0°C, use R(T) = R0[1 + AT + BT2].

R(100) = 100[1 + (3.9083×10−3)(100) + (−5.775×10−7)(1002)]

Result: 138.5055 Ω, displayed as 138.51 Ω.

Sanity check: The value must be above 100 Ω because this platinum RTD has a positive temperature coefficient over the stated range.

Example 2 — Reverse lookup from 138.51 Ω

Given: Pt100 measured/assumed element resistance ≈ 138.51 Ω.

The reverse lookup solves the same nominal characteristic for temperature, rather than using a separate linear approximation.

Result: Approximately 100°C for the nominal characteristic.

Limitation: If 138.51 Ω was measured at the ends of a 2-wire cable, subtracting or compensating lead resistance may be necessary before interpreting the value as element temperature.

RTD Resistance, Accuracy, and Calibration Are Different

Nominal characteristic
The mathematical resistance-temperature relationship used by this chart.
Tolerance / accuracy class
The permitted deviation of a sensor from the nominal characteristic under its specified standard or product requirements.
Individual calibration
Measured coefficients or correction data for one specific probe or assembly, often supplied on a calibration certificate.

Use this chart to interpret the nominal RTD relationship. For calibration, custody-transfer, acceptance testing, or high-accuracy measurement, use the actual sensor documentation, measurement setup, and calibration coefficients that govern the instrument.

Source, Range, and Data-Rights Notes

Scope: nominal α ≈ 0.00385 platinum RTD resistance-temperature behavior from −200°C through 850°C.

The reference rows on this page are independently calculated from the published Callendar–Van Dusen formulation. The page uses IEC 60751:2022 as the current industrial platinum RTD scope reference, but it does not reproduce the standard’s complete copyrighted table or layout.

Dataset and Source-Check Details

Dataset label
RTD IEC-385 characteristic · formula build 1.0
Publisher
Turn2Engineering
Source checked
August 16, 2026
Canonical units
Temperature in °C; resistance in Ω
Valid range
−200°C to 850°C; no extrapolation
Reference rows
10°C increments, calculated independently from the stated formulation
Rights approach
Calculated values and limited transformed reference display; no full reproduction of the IEC standard table
Download policy
No full standards-equivalent CSV. Copy the current calculated result instead.

RTD Resistance Chart FAQ

A Pt100 has a nominal resistance of 100 Ω at 0°C; an individual sensor can differ according to its tolerance and calibration.

Using the α ≈ 0.00385 characteristic on this page, a Pt100 is approximately 138.51 Ω at 100°C.

Yes, within the supported characteristic range, but the resistance should represent the RTD element itself rather than uncorrected lead, contact, or wiring resistance.

Lead resistance, sensor tolerance, calibration, self-heating, meter accuracy, connectors, and installation conditions can all shift the measured value away from the nominal chart.

For the α ≈ 0.00385 characteristic used here, the normalized temperature relationship is the same, but Pt1000 resistance values are ten times the corresponding unrounded Pt100 values because R0 is 1000 Ω instead of 100 Ω.

RTD Resistance Chart Summary

Use the exact lookup for temperature ↔ resistance conversion and the server-rendered table for quick Pt100, Pt500, and Pt1000 checkpoints. The page is based on the nominal α ≈ 0.00385 platinum characteristic from −200°C to 850°C and does not extrapolate outside that range.

For real measurements, confirm the RTD type, wiring method, sensor tolerance, and calibration data before treating resistance as process temperature.

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