Conversion chartLow code sensitivityLast reviewed June 6, 2026
Electrical reference chart
Temperature Conversion Chart
Use this temperature conversion chart after the calculator result to document Fahrenheit, Celsius, or Kelvin values, the original unit, the temperature context, and the next correction or coefficient calculator input.
Quick reference table
Temperature conversions keep ratings, test notes, and correction worksheets in the same unit system. Use checks such as 104 F = 40 C, 75 C = 167 F, and K = C + 273.15 before applying ambient, conductor, coefficient, or equipment-rating logic.
Common temperature conversions
| Celsius | Fahrenheit | Kelvin | Use context |
|---|---|---|---|
| 0 C | 32 F | 273.15 K | Freezing reference |
| 20 C | 68 F | 293.15 K | Room reference |
| 30 C | 86 F | 303.15 K | Common ambient planning point |
| 40 C | 104 F | 313.15 K | Warm ambient planning point |
| 75 C | 167 F | 348.15 K | Common equipment rating context |
Temperature result context checks
| Converted value is for | Record next | Why it matters |
|---|---|---|
| Ambient condition | Location, enclosure, roof, attic, or outdoor assumption | Ambient values feed correction workflows differently from equipment ratings |
| Terminal rating | Equipment label and conductor material context | Terminal temperature is not the same as surrounding air temperature |
| Test reading | Meter unit, time, load condition, and location | A field reading needs context before comparison |
| Coefficient input | Reference temperature and material | Coefficient calculations depend on the reference basis |
Which temperature calculator path to use
| Search or worksheet need | Use this chart for | Open the calculator when |
|---|---|---|
| Fahrenheit to Celsius | Quick F, C, and K lookup with the formula visible | A set of values or a report-ready conversion is needed |
| Ambient temperature correction | Confirming the temperature unit before applying a correction factor | Conductor or equipment correction depends on the project condition |
| Temperature coefficient | Keeping the reference temperature separate from the measured value | Resistance, material, or coefficient behavior must be calculated |
| Equipment rating note | Labeling terminal or insulation ratings without treating them as ambient | A final equipment or conductor selection is being reviewed |
Formula basis
C = (F - 32) x 5/9. F = C x 9/5 + 32. K = C + 273.15.
- C is temperature in degrees Celsius.
- F is temperature in degrees Fahrenheit.
- K is temperature in Kelvin.
Worked examples
Assumptions. Balanced load and line-to-line voltage assumptions behind this chart.
- Temperature conversion does not by itself apply conductor, equipment, or material correction factors.
- Equipment ratings may use specific temperature bases that must be checked before final selection.
- A converted temperature should stay tied to its context: ambient, conductor, terminal, enclosure, test reading, or material coefficient.
Code and standard notes. Planning limits that should be checked before final equipment selection.
- Use the adopted code path, equipment listing, and manufacturer data before applying temperature ratings to final installations.
How to use this chart
Worksheet checklist. Record source basis, review gaps, and assumptions before using the chart result.
- Record original valueWrite the original temperature and unit exactly as it appears in the source document, equipment label, calculator result, or field reading.
- Add converted valueAdd the converted temperature next to the original so later correction work has a clear unit basis.
- Tie to next calculatorUse the converted value in temperature correction, coefficient, or ampacity review only after the context is clear.
Common mistakes to avoid. Review these before turning chart current into an equipment decision.
- Entering Fahrenheit into a calculator field that expects Celsius and then treating the result as valid.
- Confusing ambient temperature, conductor temperature, and terminal temperature rating in the same worksheet.
- Using a converted equipment rating as if it were a measured site temperature or ambient correction value.
Frequently asked questions
These answers explain how to use the chart without turning a quick reference into a final design decision.
Why does a temperature chart matter for electrical work?
Many ratings and correction factors use a specific temperature unit or basis, so converting units first prevents mismatched assumptions.
Does this chart apply ampacity correction?
No. This chart converts temperature units only. Use the correction calculator for ampacity or material adjustment work.
Why keep the original temperature unit?
The original unit preserves the source context and helps reviewers catch Fahrenheit, Celsius, or Kelvin entry mistakes later.
When should I open the temperature calculator instead of using the chart?
Use the calculator when more than one value must be converted, when the converted value feeds another worksheet, or when the result needs a repeatable project record.
Related calculators
- Temperature ConverterConvert absolute temperatures and temperature differences between Celsius, Fahrenheit, Kelvin, and Rankine for electrical and thermal reference work.
- Temperature Correction CalculatorScreen conductor ampacity derating from ambient temperature, more than three current-carrying conductors, and the governing equipment termination limit.
- Temperature Coefficient CalculatorTCR calculator for linear ppm/°C drift checks on resistance, capacitance, inductance, voltage references, and frequency.
- Wire Ampacity CalculatorCalculate conductor ampacity with temperature correction, conductor-count adjustment, and 60°C or 75°C termination checks