If you're planning to paint a room, apartment, or full house, one question always comes first: how much paint do I need per square meter (m²)? This paint calculator helps you estimate liters, number of cans, and even approximate cost in under a minute.
Paint Calculator (m²)
Tip: Measure wall and ceiling areas in square meters. If you only want walls, leave ceiling area as 0.
How this paint calculator m2 works
The calculator uses a practical formula used by painters and contractors:
- Paintable area = (walls + ceiling) - doors/windows
- Total coated area = paintable area × number of coats
- Liters required = total coated area ÷ coverage rate
- Final liters = liters required + waste margin
- Cans = final liters ÷ can size (rounded up)
Because paint is sold in fixed can sizes, rounding up is important. Even a small shortfall can delay your project and may create color consistency issues if you buy from a different batch later.
Why calculating paint in m² matters
Estimating by eye often leads to overspending or running out mid-job. A square-meter-based approach gives you a repeatable and reliable estimate, especially when comparing brands that use different packaging sizes and coverage claims.
It also helps with:
- Budget planning before renovation starts
- Comparing contractor quotes
- Reducing material waste
- Planning delivery and storage
Choosing the right coverage value (m² per liter)
Typical ranges
- Matte interior paint: 8–12 m²/L
- Eggshell/satin: 9–13 m²/L
- Gloss/enamel: 10–14 m²/L
- Masonry/exterior coatings: 6–10 m²/L
Always check the paint can label. Manufacturer coverage is usually measured under ideal conditions on smooth, sealed surfaces. Rough walls, patchy repairs, deep color changes, and textured finishes can reduce real-world coverage.
Example calculation
Suppose you have:
- Walls = 60 m²
- Ceiling = 20 m²
- Doors/windows = 8 m²
- 2 coats
- 10 m²/L coverage
- 10% extra margin
The math:
- Paintable area = 60 + 20 - 8 = 72 m²
- Total coated area = 72 × 2 = 144 m²
- Base liters = 144 ÷ 10 = 14.4 L
- With 10% extra = 14.4 × 1.10 = 15.84 L
If cans are 2.5 L each, you'll need 7 cans (17.5 L total).
Common mistakes to avoid
1) Forgetting the second coat
Many surfaces need at least two coats for uniform color and durability.
2) Ignoring surface texture
Textured plaster and rough masonry can consume significantly more paint.
3) Not accounting for primer
If you're painting over stains, fresh drywall, or dark colors, add primer calculations separately.
4) Using exact minimum quantities
Leave a buffer for roller absorption, tray waste, and future touch-ups.
Quick measuring tips
- Measure each wall as width × height, then sum all walls.
- Measure ceiling separately (length × width).
- Subtract major openings only (doors and large windows).
- Keep all units in meters to stay consistent in m².
FAQ
How many square meters does 1 liter of paint cover?
Most paints cover around 8 to 12 m² per liter per coat. Check your product label for exact values.
Should I include ceilings in paint calculations?
Yes, if you plan to paint them. This calculator lets you add ceiling area separately.
How much extra paint should I buy?
A 5–15% margin is common. Use a higher margin for textured or porous surfaces.
Can I use this for exterior walls?
Yes, but use an exterior-appropriate coverage rate and usually a slightly higher waste margin due to surface irregularities.
Final thoughts
A good paint estimate saves time, money, and frustration. Use the calculator above to get a fast m²-based estimate, then verify it against the paint manufacturer's specifications. If in doubt, round up and keep leftover paint for future touch-ups.