Type K millivolt to temperature converter
Convert a Type K thermocouple reading in millivolts to degrees Celsius against the 17 verified reference points from −200 °C to +1370 °C at a 0 °C reference junction.
Result
Enter a measured EMF in millivolts to see the equivalent process temperature.
-°C
Outside the verified table
Method
Linear interpolation between adjacent published reference points at 100 °C spacing. The bracket used is printed with every result, so the interval is visible rather than assumed.
Frequently Asked Questions (FAQ)
What reference junction does this Type K converter assume?
0 °C. The table values behind the calculator are EMF at a 0 °C reference junction, so a reading taken with an ice-point or compensated reference is the correct input. If your cold junction is at ambient temperature the millivolt figure at the terminals already differs from this table and has to be corrected before conversion.
Why is the answer interpolated rather than calculated from a formula?
Because the verified values we hold are the published reference points, not a fitted polynomial. Linear interpolation between adjacent points is transparent and reproducible: the tool shows the two points it used so you can see the interval for yourself rather than trusting an opaque curve.
How accurate is the result between two reference points?
The table is stored at 100 °C spacing, and Type K curvature between adjacent points makes the interpolated value very slightly different from a true reference-table lookup. The tool states the bracket it used; where a reading must sit inside a tight class band, compare against the full table or the batch certificate rather than a single interpolated figure.
What happens if I enter a value outside the table?
The tool returns no answer instead of extrapolating. The verified span runs from −200 °C to +1370 °C, and printing a number beyond it would be an invented figure, not a measurement.
Matching instrument or wire?
Send the alloy, gauge and accuracy class, we supply Type K bare and stranded wire with a furnace-batch-traceable EMF certificate.