Picas to Millimeters Converter
Enter the length in picas below to convert it to millimeters.
Convert Picas to Millimeters
Enter a value in picas (pc) to convert to millimeters (mm).
Picas to Millimeters Conversion Chart (1–40 Continuous)
Continuous 1 to 40 picas lookup table with exact decimals and reduced nearest 1/64 fractions. Highlighted rows mark common shop and ruler values.
| Picas (pc) | Decimal (mm) | Fraction — Nearest 1/64 (Reduced) | Nearest 1/16 (Tape) |
|---|---|---|---|
1 pc★ Common | 4.233333 mm | 4 15/64 mm | 4 1/4 mm |
2 pc★ Common | 8.466667 mm | 8 15/32 mm | 8 7/16 mm |
3 pc★ Common | 12.7 mm | 12 45/64 mm | 12 11/16 mm |
4 pc | 16.933333 mm | 16 15/16 mm | 16 15/16 mm |
5 pc★ Common | 21.166667 mm | 21 11/64 mm | 21 3/16 mm |
6 pc★ Common | 25.4 mm | 25 13/32 mm | 25 3/8 mm |
7 pc | 29.633333 mm | 29 41/64 mm | 29 5/8 mm |
8 pc★ Common | 33.866667 mm | 33 55/64 mm | 33 7/8 mm |
9 pc | 38.1 mm | 38 3/32 mm | 38 1/8 mm |
10 pc★ Common | 42.333333 mm | 42 21/64 mm | 42 5/16 mm |
11 pc | 46.566667 mm | 46 9/16 mm | 46 9/16 mm |
12 pc★ Common | 50.8 mm | 50 51/64 mm | 50 13/16 mm |
How to Convert Picas to Millimeters
To convert picas to millimeters, multiply the length by the following conversion ratio: 4.2333333 millimeters/pica.
Since one pica is equal to 4.2333333 millimeters, you can use this simple formula to convert:
The length in millimeters is equal to the length in picas multiplied by 4.2333333.
For example, here's how to convert 5 picas to millimeters using the formula above.
How Many Millimeters Are in a Pica?
There are 4.2333333 millimeters in a pica, which is why we use this value in the formula above.
Our pica fraction and decimal calculator can convert picas and millimeters, and it automatically converts the results to US customary, imperial, and SI metric values.
Picas and millimeters are both units used to measure length. Keep reading to learn more about each unit.
How to Convert Picas to Fractional Inches (1/16″, 1/32″ & 1/64″)
Plain-language method for turning decimal inches into a standard tape-measure or machinist ruler fraction
Calculators give you a decimal number (such as 0.833333 in), but tape measures and woodworking rulers are marked in binary fractions of an inch—most commonly 1/16″ on carpenter tapes, 1/32″ on fine woodworking rules, and 1/64″ on machinist scales.
Here is the step-by-step worked example for converting 5 picas (pc) into fractional inches:
- Find the decimal inches result: Convert 5 pc to inches to get 0.833333 in.
- Separate the whole inches from the decimal part: Keep the whole number 0 aside, leaving the decimal remainder 0.833333.
- Multiply the decimal part by your desired fraction denominator (16, 32, or 64) and round half up: Multiply 0.833333 by 16, 32, or 64, then round to the nearest whole number (values ending in .5 round up).
- Reduce the fraction to lowest terms: If the rounded top number (numerator) is even, divide both top and bottom by 2 (or their Greatest Common Divisor) until the top number is odd, then combine with your whole inches.
What Is a Pica?
A pica is a unit of length equal to 0.0042333 meters (m), the base unit for length. Typographical unit equal to 12 points or 1/6 of an inch (4.2333 mm). [1]
The pica is classified as a standard unit of length. Picas can be abbreviated as pc; for example, 1 pica can be written as 1 pc.
When working with picas (pc) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, picas (pc) are widely used across fine-tolerance laboratory, analytical, and micro-scale length measurements within international standard workflows, engineering documentation, and technical data sheets.
What Is a Millimeter?
A millimeter is a metric unit of length equal to one-thousandth (1/1,000) of a meter or one-tenth (1/10) of a centimeter. By international definition, there are exactly 25.4 millimeters in one inch. [2]
The millimeter, or millimetre, is a standard SI metric unit of length. Millimeters can be abbreviated as mm; for example, 1 millimeter can be written as 1 mm.
In the metric system, "milli" is the prefix for thousandths, or 10⁻³. Millimeters are the default unit on mechanical engineering drawings and architectural blueprints worldwide.
Millimeters are commonly measured using metric steel rules, digital vernier calipers, depth gauges, and micrometers in CNC machining, 3D printing, automotive fasteners, and precision manufacturing.
When converting length between picas (pc) and millimeters (mm), keep full floating-point precision (1 pc = 4.2333333 mm; 1 mm = 0.2362205 pc) during intermediate calculations and round only the final millimeter figure to match your instrument tolerance.
More Pica & Millimeter Conversions
Need to calculate in the opposite direction? Use our millimeters to picas calculator to switch your starting unit immediately. You can also explore related tools such as converting millimeters to picas, converting inches to millimeters, or converting micrometers to millimeters.
Convert from Picas
Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Length)·Length Metrology Standard — Picas (pc) to Millimeters (mm)
- [2]BIPM SpecificationBIPM (SI Base Unit: Metre (m))·Unit Specifications: Pica (Typography) (pc) & Millimeter (mm)
- [3]NIST HB 133 ReferenceNIST HB 133 (NIST Handbook 133 (2019 Ed.))·Conversion Factors & Mathematical Basis (pc to mm)