Convert Pica to Millimeter
Convert picas to millimeters instantly. 1 pica = 4.2333333 millimeter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Millimeter to Pica converter for the reverse conversion.
Units explained
Pica
A pica is a typographic unit equal to exactly 12 points, or 1/6 inch (about 4.233 mm). It is used for measuring column widths and large typographic elements.
The PostScript pica of 12 points = 1/6 inch was standardised in 1984 alongside the PostScript point. Traditional pre-1984 picas varied slightly (e.g., the American pica was 0.166 inch, very close but not identical).
Picas are used for column widths in newspaper and magazine layout (typical column is 11–15 picas), line spacing in book design, and large typographic measurements. Mostly used by professional typesetters.
Modern PostScript pica defined in 1984 at 12 points = 1/6 inch; older typographic systems used slightly different pica values.
Millimeter
A millimeter is a metric unit of length equal to one thousandth of a meter (1/1000 m). It is the standard small-scale unit in the SI system and is widely used wherever sub-centimeter precision matters.
The millimeter was defined alongside the meter when France adopted the metric system in 1795, using the standard SI prefix milli- (from Latin mille, "thousand") to denote one-thousandth.
Millimeters are used in engineering drawings, machining, manufacturing, paper sizes, rainfall measurement, and any context where dimensions below one centimeter need to be specified clearly. Most rulers worldwide are marked in millimeters.
Adopted in 1795 in France as part of the original metric system; standardized internationally by the Metre Convention in 1875 and confirmed in the SI in 1960.
Pica to Millimeter conversion formula
The relationship between picas and millimeters:
To convert picas to millimeters, multiply the value in picas by 4.2333333. To reverse, multiply millimeters by 0.2362204743.
How to use this converter
Type a value into the calculator. The result in millimeters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Millimeter to Pica converter for the reverse direction.
Step-by-step: convert picas to millimeters
- Write down the value in picas (pc).
- Multiply that value by the factor 4.2333333.
- The product is the equivalent value in millimeters (mm).
- To reverse, multiply the millimeter value by 0.2362204743.
Worked examples
Example 1 — Convert 1 pc to mm:
1 × 4.2333333 = 4.2333333 mm
Example 2 — Convert 100 pc to mm:
100 × 4.2333333 = 423.33333 mm
Real-world example — Hardware-scale dimensions
A 10-pica fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between picas and millimeters daily when mixing metric and imperial tools.
10 pc × 4.2333333 = 42.333333 mm
Real-world example — Postcard and small-object dimensions
A postcard is about 5 picas wide. Converting to millimeters is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 pc × 4.2333333 = 21.1666665 mm
Real-world example — Ruler-scale measurements
A 30-pica school ruler converts cleanly to millimeters — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 pc × 4.2333333 = 126.999999 mm
Pica to Millimeter conversion table
Standard reference values for converting picas to millimeters:
| Pica [pc] | Millimeter [mm] |
|---|---|
| 0.01 | 0.042333333 |
| 0.1 | 0.42333333 |
| 1 | 4.2333333 |
| 2 | 8.4666666 |
| 3 | 12.6999999 |
| 4 | 16.9333332 |
| 5 | 21.1666665 |
| 10 | 42.333333 |
| 20 | 84.666666 |
| 30 | 126.999999 |
| 40 | 169.333332 |
| 50 | 211.666665 |
| 100 | 423.33333 |
| 500 | 2116.66665 |
| 1000 | 4233.3333 |
Frequently asked questions
How many millimeters is 1 pica?
How do I convert picas to millimeters?
How do I convert millimeters back to picas?
How many millimeters is 100 picas?
Popular length unit conversions
Convert Pica to other length units
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Metric / SI (4 units)
Imperial / US Customary (4 units)
Typographic (2 units)
Sources & references
Conversion factor (1 pc = 4.2333333 mm) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.