Paint Calculator for Walls, Ceilings and Cans
Calculate paint litres, can counts, coat requirements, coverage rate and waste margin for interior walls and ceilings.
Estimation Inputs
Net wall or ceiling paint area.
Total finish coats to apply.
Average coverage per litre.
Extra paint allowance.
Litres in one paint can.
Pricing & Rates
Price per purchase unit used by this calculator.
Applied to the estimated purchase quantity.
Use 0 if tax is not applicable.
Quantity Takeoff
total Paint Area
100
paint Required Litres
10.5
purchase Cans
3
Formula Trace
Total Paint Surface Area:
Net Area * Number of Coats
50.00 m² * 2
= 100.000 m²
Raw Paint Volume Required:
Total Paint Area / Coverage rate
100.00 m² / 10.0 m²/L
= 10.000 L
Paint Volume (with Waste):
Raw Paint Volume * (1 + Wastage % / 100)
10.00 L * (1 + 5.0 / 100)
= 10.500 L
Purchase Cans Required:
ceil(Paint Volume with Waste / Can Size)
ceil(10.50 L / 4.0 L)
= 3.000 cans
Estimate Outcome
Calculation guide and formulas
Use this paint calculator to estimate litres and cans for walls or ceilings based on total area, number of coats, paint coverage, can size and waste.
Understand the units, allowances and purchase rounding (English).
Worked example
A 50 m² surface with 2 coats equals 100 m² of coverage. At 10 m² per litre, it needs 10 L. With 5% waste, plan 10.5 L or 3 cans of 4 L.
Frequently asked questions
Q: How many coats of paint are usually needed?
A: Most interior walls need two finish coats after primer. Dark colour changes or porous surfaces may need extra coverage.
Q: Why does paint coverage vary?
A: Coverage depends on surface porosity, primer, paint type, roller texture and application quality.