Coating unit converter

Type in either box. 1 mil is exactly 25.4 µm.

This tool is a reference aid. Before you act on a result, check it against your specification and the product data sheet.

Where each one shows up

• µm and mils: film thickness and surface profile (US specifications use mils).
• °C and °F: air, steel and dew point temperatures.
• MPa and psi: pull-off adhesion results.
• m²/L and ft²/US gal: spreading rates on data sheets.

How to use it

Type a value in either box of a row; the other box follows. Convert the specification's limit once and compare your readings with it, rather than converting every reading.

Worked examples

• Profile: a specified 2–3 mil profile is 51–76 µm.
• Replica tape: its incompressible film is 2.0 mils, which is 50.8 µm.
• Pull-off: 7 MPa is about 1,015 psi (1 MPa ≈ 145 psi).
• Spreading rate: 70 % volume solids at 200 µm gives 10 × 70 ÷ 200 = 3.5 m²/L, about 143 ft²/US gal. The US form gives the same: 1,604 × 0.70 ÷ 7.87 mils.

Traps

• A temperature difference is not a temperature. 20 °C is 68 °F, but a margin of 3 °C above the dew point is 5.4 °F, not 37.4 °F. For a difference, multiply by 9 ÷ 5 and do not add 32. SSPC-PA 1 rounds the margin to 5 °F.
• Conductivity units: 1 mS/m = 10 µS/cm. A limit of 1,000 µS/cm reads 100 mS/m on a meter set to mS/m.
• Rounding: round only the final answer. A mil rounded to 25 µm puts 10 mils 4 µm short.

Related: All calculators · Dew point calculator · Paint consumption calculator · Glossary.