Paint Calculator
Buying paint is expensive — too little and you have to make another trip, too much and you've wasted money. This calculator tells you exactly how many litres of paint you need based on the surface area, paint coverage, and number of coats.
結果
4 L
Paint needed
- Per coat
- 2 L
- Total surface
- 40 m²
How this was calculated
- 1Total area to paint20 m² × 2 lagen = 40 m²
- 2Divide by coverage40 m² ÷ 10 m²/L = 4 L
公式
Litres of paint = (Area × Number of coats) ÷ Coverage per litre
Paint spreads out: 1 litre can cover 10-15 m² (depends on colour, surface, and quality). If you want to paint a 20 m² wall twice, that's 40 m². Divided by 10 m²/L = 4 litres. Always check your paint can for exact coverage data — it varies a lot.
ステップ解説
- 1Enter the surface area you want to paint in square metres.
- 2Enter your paint's coverage (check on the paint can).
- 3Enter how many coats you want (standard is 2).
- 4Read off how many litres you need — go to the store!
計算例
Living room: 30 m², coverage 10 m²/L, 2 coats
→ (30 × 2) ÷ 10 = 6 litres needed
Bedroom: 20 m², coverage 12 m²/L, 1 coat
→ (20 × 1) ÷ 12 = 1.67 litres (round to 2L)
Front door (outdoor): 5 m², coverage 8 m²/L, 3 coats
→ (5 × 3) ÷ 8 = 1.88 litres (round to 2L)
Reference table
| Paint type | Coverage m²/L |
|---|---|
| Matt (interior) | 10-12 |
| Gloss (interior) | 12-14 |
| Exterior | 8-10 |
Dark colours often have lower coverage. Always check your paint can.
よくある間違い
- Planning only one coat — experts recommend at least 2 coats for good results.
- Not checking the coverage on the paint can — can differ a lot from standard.
- Not accounting for surface prep: unprepared walls absorb more paint.
活用シーン
- Interior walls: Calculate how many paint cans you need.
- Outdoor painting: More coats for weather resistance.
- Budgeting: Know exactly how much you'll spend.
よくある質問
How many coats of paint do I need?
Standard is 2 coats for indoors, 3 for outdoors. First coat spreads pigments, second gives deep coverage. For very dark colours a third coat may be needed. Check your paint can for specific recommendations.
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