Thickness Conversion Calculator

Convert thickness values, compare material gauges, calculate tolerance ranges, process batches, and export clear results with formulas, tables, and practical engineering references for projects.

Conversion inputs

Use zero when no tolerance applies.
Compares nominal and measured thickness.
Batch data overrides the single value.

Recent conversion history

Completed conversions appear here.

Formula used

Linear unit conversion
Thickness in metres = Input thickness × Source unit factor
Converted thickness = Thickness in metres ÷ Target unit factor

Tolerance range
Minimum = Nominal thickness − Tolerance
Maximum = Nominal thickness + Tolerance

AWG diameter
Diameter in inches = 0.005 × 92((36 − AWG) ÷ 39)

Non-ferrous B&S gauge approximation
Thickness in inches = 0.324861 × 0.890526gauge

Gauge numbers are standards, not universal linear units. The selected material controls the nominal gauge thickness. Verify critical work against the manufacturer’s current specification.

How to use this calculator

  1. Enter one thickness or paste several batch values.
  2. Select the source unit and required target unit.
  3. Choose the material when either unit uses gauge.
  4. Add tolerance, actual thickness, or rounding settings.
  5. Select Convert thickness to display complete results.
  6. Copy, print, share, or export the result table.

Worked examples

ExampleInputConversionResult
Plastic film50 µmMicrometres to millimetres0.05 mm
Sheet thickness1.5 mmMillimetres to inches0.059055 in
Coating4 milMil to micrometres101.6 µm
Glass0.25 inInches to millimetres6.35 mm
Steel gauge16 gaugeStandard steel to inches0.0598 in nominal

Common conversion reference

RelationshipExact or standard value
1 inch25.4 millimetres
1 millimetre1,000 micrometres
1 micrometre1,000 nanometres
1 mil or thou0.001 inch
1 mil or thou25.4 micrometres
1 foot12 inches
1 yard3 feet

Frequently asked questions

What is thickness conversion?

Thickness conversion expresses one measured depth in another unit. The physical thickness remains unchanged during the calculation. Only its numerical representation and unit are changed.

What is a mil?

A mil is one thousandth of an inch. It is also called a thou in some industries. One mil equals exactly 25.4 micrometres.

Is a micron the same as a micrometre?

Yes, micron is the common name for micrometre. Its symbol is µm in scientific notation. One micrometre equals one thousand nanometres.

Why does gauge depend on material?

Gauge systems developed from manufacturing and weight standards. The same gauge number may represent different thicknesses. Always select the correct material before converting gauge.

Does a larger gauge mean thicker material?

Usually, larger gauge numbers represent thinner sheet or wire. This inverse relationship can confuse first-time users. Check the selected standard before ordering material.

How is tolerance applied?

Tolerance is entered in the selected source unit. The calculator converts its minimum and maximum limits. Gauge inputs require conversion into linear units first.

What does nominal thickness mean?

Nominal thickness is the stated or labelled dimension. Actual thickness may differ because of manufacturing tolerances. Compare measurements using the optional actual value field.

Can I convert several values together?

Yes, paste comma-separated or line-separated values into batch mode. The calculator processes up to five hundred entries. Results can be downloaded as a CSV file.

When should scientific notation be used?

Scientific notation helps display extremely small thickness values. It is useful for coatings, films, and nanomaterials. Enable it before calculating the required conversion.

Are gauge results exact?

Gauge results are nominal values from established standards. Coatings and manufacturing processes can alter measured thickness. Confirm important dimensions using supplier documentation and instruments.

What custom factor should I enter?

Enter how many metres equal one custom unit. For example, 0.002 means one unit equals two millimetres. The factor must always be greater than zero.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.