Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- One rectangular roof plane; no sheet offcut reuse, penetrations or extra waste. Required overlaps must come from the supplier.
Example Calculation
- Roof plane width: 10 m
- Roof slope length: 5 m
- Sheet width: 1 m
- Sheet length: 3 m
- Side overlap: 0.1 m
- End overlap: 0.2 m
A 10×5 m roof plane with 1×3 m sheets and 0.1/0.2 m overlaps needs 11 columns × 2 rows.
Frequently asked questions
How do I use this calculator?
Enter roof plane width, roof slope length, sheet width, sheet length, side overlap, end overlap. The result updates automatically. Use Reset to restore the example values.
What method does it use?
columns=max(1,ceil((width−overlap)/(sheet width−overlap))); rows similarly.. One rectangular roof plane; no sheet offcut reuse, penetrations or extra waste. Required overlaps must come from the supplier.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.