Paint Quantity Calculator
Calculate the amount of paint needed to paint rooms or walls
Room Dimensions
~20 sq ft each
~15 sq ft each
sq ft per litre (typical emulsion paint)
Enter room dimensions and click Calculate
How to Use
- Enter the Room Dimensions — length, width, and wall height in feet or metres.
- Enter the number of Doors and Windows to subtract their area automatically.
- Select the number of Coats (typically 2 for repainting, 3 for new walls).
- Enter the paint's Coverage Rate (check the paint tin — typically 10–12 sq m/litre).
- Click Calculate to see total paintable area, litres required, and number of paint tins to buy.
Why Use a Paint Calculator?
Buying too little paint means a mid-project trip to the store — and potentially a colour mismatch if the batch number changes. Buying too much wastes money and results in unused paint that is difficult to dispose of responsibly. A paint calculator helps you buy just right — plus a small buffer for touch-ups.
Paintable Area Calculation
Wall Area = 2 × (Length + Width) × Height
Subtract: Doors (≈ 2 sq m each), Windows (≈ 1.5 sq m each)
+ Ceiling (Length × Width) if painting ceiling
Net Area = Wall Area − Doors − Windows [+ Ceiling]
Subtract: Doors (≈ 2 sq m each), Windows (≈ 1.5 sq m each)
+ Ceiling (Length × Width) if painting ceiling
Net Area = Wall Area − Doors − Windows [+ Ceiling]
Standard Paint Coverage (India)
| Paint Type | Coverage per Litre |
|---|---|
| Interior emulsion (economy) | 9 – 10 sq m |
| Interior emulsion (premium) | 11 – 13 sq m |
| Exterior weather coat | 8 – 10 sq m |
| Primer / wall putty | 6 – 8 sq m |
| Enamel / oil-based | 12 – 14 sq m |
Buying Tips
- Always buy 10–15% extra for touch-ups and corner wastage.
- Check batch numbers when buying multiple tins — different batches can have subtle colour variations.
- Store unused paint with the lid sealed tightly and inverted — it can last 2–3 years this way.
- Ask for a test pot (100–200 ml) before committing to a full shade — colours look different on walls than on chips.
Frequently Asked Questions
The calculator gives a reliable estimate based on standard spreading rates (typically 10–12 sq m per litre for emulsion paints). Actual consumption varies by: surface texture (rough surfaces absorb more), number of coats, paint brand and quality, and painting technique. Always buy 10–15% extra to account for touch-ups and wastage.
New/bare walls: 1 primer coat + 2 finish coats minimum. Repainting (light colour over light): 1–2 coats. Repainting (dark over light or light over dark): 2–3 coats. The calculator defaults to 2 coats; adjust using the coats selector for your situation.
Measure the length and width of each wall, multiply to get area, then subtract doors (≈2 sq m each) and windows (≈1.5 sq m each). Add the ceiling area if painting it. Our calculator does this automatically — enter the room dimensions, number of doors and windows, and it computes net paintable area.
Asian Paints Tractor Emulsion: ~10–11 sq m/litre per coat. Berger Easy Clean: ~11–12 sq m/litre. Dulux Weathershield: ~9–10 sq m/litre (exterior). Premium paints generally have better coverage than economy grades. Check the paint tin's data sheet for the exact spreading rate.
Most interior emulsion paints have a density of approximately 1.3–1.5 kg/litre. A 4-litre tin typically weighs 5–6 kg. Paint is always sold by volume (litres), not weight, so use litres for calculations. Our calculator outputs in litres.