What this converter does
This converter turns section modulus in cubic millimetres into cubic inches and back. It also covers cm³ and m³ — every pair uses an exact factor. Type a value, pick your units, and read the result as you type.
Section modulus (S or Z) sets a beam’s bending capacity. One cubic inch is 16,387 mm³. For the related area moment, see the mm⁴ to in⁴ converter.
The units it covers
Section modulus is a volume (length³); each unit converts through the cubic millimetre.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Cubic millimetre | mm³ | 1 | Metric section tables |
| Cubic centimetre | cm³ | 1000 | Steel section catalogues |
| Cubic inch | in³ | 16387.064 | US section tables |
| Cubic metre | m³ | 1e9 | Large sections |
The formula
Each unit has a fixed value in cubic millimetres, so section modulus converts through the mm³ once:
result = value × factor_from ÷ factor_toWhere:
- value = the number you typed, in the “from” unit
- factor_from = the “from” unit’s value in cubic millimetres
- factor_to = the “to” unit’s value in cubic millimetres
Worked example
Convert 50,000 mm³ of section modulus to cubic inches.
1 in³ = 16,387.064 mm³50000 ÷ 16387.064 = 3.052 in³So 50,000 mm³ is about 3.05 cubic inches of section modulus.
The units in this example
The metric unit for section modulus in steel and timber tables, where S sets bending strength.
- 1 cm³ = 1,000 mm³
- 1 in³ = 16,387 mm³
- 1 mm³ ≈ 6.10e-5 in³
- 1 m³ = 1e9 mm³
The US unit for section modulus, quoted in AISC steel section tables.
- 1 in³ = 16,387 mm³
- 1 in³ ≈ 16.39 cm³
- 1 in³ ≈ 1.639e-5 m³
- 1 in³ = 1 in³