屋根面積計算機

共有リンク

はじめに

Roof Area Calculator — True roof area from footprint area and pitch angle. Enter Footprint area (m²), Pitch angle (°) to get an instant, accurate result.

計算式

Roof (sloped) area = footprint area ÷ cos(pitch angle), the standard formula for converting a flat footprint into actual sloped roof surface area.

ステップごとの説明

Enter the Footprint area (m²).
Enter the Pitch angle (°).
Click Calculate to see your result instantly.

実例

Example: With Footprint area (m²) = 100, Pitch angle (°) = 30, the Roof Area Calculator gives Roof Area M2: 115.4701.

よくある質問

Why divide by cosine of the pitch angle?

A sloped roof surface is longer than its flat footprint by a factor of 1/cos(angle) — steeper roofs (larger angles) have proportionally more surface area.

How do I find my pitch angle if I only know rise/run?

Use the Roof Pitch calculator first to convert rise and run into degrees, then use that angle here.

What inputs does the Roof Area Calculator need?

You'll need to provide: Footprint area (m²), Pitch angle (°). All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.

How accurate is the Roof Area Calculator?

The Roof Area Calculator applies the formula exactly as calculated — Roof (sloped) area = footprint area ÷ cos(pitch angle), the standard formula for converting a flat footprint into actual sloped roof surface area. — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.

Is the Roof Area Calculator free to use?

Yes, the Roof Area Calculator is completely free, requires no signup, and runs instantly in your browser.