Feet Inch Dimension Arithmetic calculator.
Add or subtract lengths, multiply two lengths into area, or divide lengths into a ratio with fractional input.
Your inputs
Use measurements from your plan and properties from your chosen product. Any prefilled values are illustrative.
A clear estimate starts here.
Enter your dimensions and product details to see the quantity and purchase breakdown.
Formula and assumptions
How this calculation works.
US inputs accept feet, inches and fractions; metric inputs accept the displayed unit. Arithmetic is dimension-aware: two lengths multiply to area and divide to a dimensionless ratio. Signed answers remain mathematical measurements rather than purchase quantities. This is a two-operand calculation, not a general expression parser.
A worked example
Illustrative inputs only. Product properties and design dimensions are not recommendations for your project.
- Operation
- Add lengths
- First length
- 0.61 m
- Second length
- 0.3 m
Dimension arithmetic result: 0.91 m
Two-operand dimensional arithmetic. Signed results describe measurements, not material purchase quantities.
Before you purchase
Use dimensions from your plan and properties from your chosen product. Any design spacing, section or fixing pattern must already be specified.
Method: dimensional arithmetic and user-supplied specifications. Software checks: 2026-10-05. Calculation and review policy.