使い方
A better estimate in three steps.
- 01
Enter the room dimensions and subtract openings.
- 02
Set coats and the coverage printed on your paint can.
- 03
Compare waste allowances before buying.
ホーム・DIY
塗料計算
Estimate wall area, paint volume, can count, and total paint cost—with doors, windows, coats, and waste included.
01
数値を入力
入力すると結果がすぐ更新されます。
基本式
The math behind the result.
Paint needed = (net wall area × coats × (1 + waste rate)) ÷ paint coverageよくある質問
Useful before you decide.
How much extra paint should I buy?
A 10% allowance is a practical starting point for normal walls. Detailed trim, textured surfaces, repairs, and strong color changes may require more.
Does this include the ceiling?
Not automatically. Add the ceiling as a separate rectangular surface or include its area by increasing the calculated paintable area.
Why can the can count look high?
The calculator rounds up to whole cans so the estimate reflects what can actually be purchased.