NTC 20k β3950 thermistor chart: resistance table (°F)
Resistance in ohms of an NTC thermistor with R₂₅ = 20kΩ and β = 3950 K, calculated with the Beta model from -40 °F to 257 °F. Real parts follow their manufacturer’s R/T table, which can differ from the Beta model by a few percent far from 25 °C; use these values for design estimates and check critical points against the datasheet.
Each row is a 10-degree step; the column adds the units digit (subtracts it in rows below zero). Example: 100 + 5 → 105 °F.
| °F | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|
| -40 | 803720 | |||||||||
| -30 | 541830 | 563150 | 585420 | 608680 | 632990 | 658380 | 684920 | 712660 | 741660 | 771990 |
| -20 | 371890 | 385850 | 400410 | 415580 | 431410 | 447920 | 465130 | 483100 | 501840 | 521410 |
| -10 | 259550 | 268860 | 278550 | 288630 | 299130 | 310060 | 321430 | 333280 | 345630 | 358490 |
| -0 | 184010 | 190320 | 196880 | 203690 | 210770 | 218130 | 225780 | 233730 | 242000 | 250600 |
| 0 | 184010 | 177930 | 172080 | 166450 | 161020 | 155800 | 150760 | 145910 | 141230 | 136720 |
| 10 | 132380 | 128190 | 124150 | 120250 | 116490 | 112870 | 109370 | 105990 | 102730 | 99586 |
| 20 | 96550 | 93618 | 90787 | 88052 | 85411 | 82859 | 80394 | 78012 | 75709 | 73484 |
| 30 | 71332 | 69252 | 67241 | 65296 | 63415 | 61595 | 59835 | 58131 | 56483 | 54888 |
| 40 | 53344 | 51849 | 50402 | 49001 | 47644 | 46330 | 45057 | 43823 | 42629 | 41471 |
| 50 | 40349 | 39262 | 38208 | 37186 | 36196 | 35235 | 34304 | 33400 | 32524 | 31674 |
| 60 | 30850 | 30050 | 29273 | 28520 | 27788 | 27079 | 26389 | 25720 | 25071 | 24440 |
| 70 | 23827 | 23232 | 22654 | 22092 | 21546 | 21016 | 20501 | 20000 | 19513 | 19040 |
| 80 | 18580 | 18133 | 17698 | 17275 | 16864 | 16463 | 16074 | 15696 | 15327 | 14969 |
| 90 | 14620 | 14281 | 13950 | 13629 | 13316 | 13011 | 12714 | 12425 | 12144 | 11870 |
| 100 | 11603 | 11343 | 11090 | 10843 | 10603 | 10369 | 10140 | 9918 | 9701.2 | 9489.9 |
| 110 | 9283.9 | 9083 | 8887.2 | 8696.3 | 8510.1 | 8328.5 | 8151.4 | 7978.7 | 7810.2 | 7645.8 |
| 120 | 7485.5 | 7329 | 7176.4 | 7027.4 | 6882 | 6740.1 | 6601.6 | 6466.4 | 6334.4 | 6205.5 |
| 130 | 6079.7 | 5956.9 | 5836.9 | 5719.8 | 5605.3 | 5493.6 | 5384.4 | 5277.8 | 5173.6 | 5071.8 |
| 140 | 4972.3 | 4875.1 | 4780.2 | 4687.4 | 4596.6 | 4508 | 4421.3 | 4336.6 | 4253.7 | 4172.7 |
| 150 | 4093.6 | 4016.1 | 3940.4 | 3866.3 | 3793.9 | 3723.1 | 3653.8 | 3586 | 3519.7 | 3454.8 |
| 160 | 3391.3 | 3329.2 | 3268.4 | 3208.9 | 3150.7 | 3093.7 | 3038 | 2983.4 | 2929.9 | 2877.6 |
| 170 | 2826.4 | 2776.2 | 2727.1 | 2679 | 2631.9 | 2585.8 | 2540.6 | 2496.4 | 2453.1 | 2410.6 |
| 180 | 2369 | 2328.3 | 2288.3 | 2249.2 | 2210.9 | 2173.3 | 2136.5 | 2100.5 | 2065.1 | 2030.4 |
| 190 | 1996.5 | 1963.2 | 1930.5 | 1898.5 | 1867.2 | 1836.4 | 1806.2 | 1776.6 | 1747.6 | 1719.2 |
| 200 | 1691.3 | 1663.9 | 1637.1 | 1610.7 | 1584.9 | 1559.6 | 1534.7 | 1510.3 | 1486.4 | 1462.9 |
| 210 | 1439.8 | 1417.2 | 1395 | 1373.3 | 1351.9 | 1330.9 | 1310.3 | 1290.1 | 1270.2 | 1250.7 |
| 220 | 1231.6 | 1212.8 | 1194.4 | 1176.3 | 1158.5 | 1141 | 1123.9 | 1107 | 1090.5 | 1074.2 |
| 230 | 1058.3 | 1042.6 | 1027.2 | 1012.1 | 997.2 | 982.6 | 968.25 | 954.14 | 940.29 | 926.67 |
| 240 | 913.29 | 900.14 | 887.22 | 874.52 | 862.03 | 849.76 | 837.69 | 825.84 | 814.18 | 802.72 |
| 250 | 791.45 | 780.37 | 769.47 | 758.76 | 748.23 | 737.87 | 727.69 | 717.67 |
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