Exterior Paint Calculator
Estimate paint for measured exterior wall sections, siding or façade areas. Use the product label for coverage and keep trim or different colors in separate groups.
Group rooms by color and product. Paint and primer are rounded separately. Defaults are an example; use your measurements and product label.
Product 1
Example · edit your measurements
Exterior finish
- Net surface area
- 32.4 m²
- Required with allowance
- 7.128 L
- Cans to buy
- 3
- Purchase volume
- 7.5 L
- Volume above requirement
- 0.372 L
- Known material cost
- Price not entered
Displayed quantities are rounded; package counts use full precision. Use the same currency for all prices. Labor, preparation, tools, tax and delivery are excluded. Product groups are rounded independently; areas in a group are summed first.
From quantity to appearance
Choose a wall color
Only the selected material or color enters the design brief. Cans, boxes and cost stay in this calculation. The preview shows a design direction, not installation specifications.
How exterior paint is calculated
Net exterior area is the sum of measured wall rectangles minus openings. Paint needed = net area × coats × (1 + allowance) ÷ product coverage per coat. Cans are rounded up from the full precision result.
Measure façade sections separately
Split gables, additions and other sections into rectangles or enter an already measured net area. Keep siding, trim, doors and different colors in separate product groups because coverage and coats may differ.
What this estimate does not verify
The calculator does not infer façade area from a photo, model roof pitch, account for texture or certify ladder access, preparation, primer, code or contractor quantities. Follow the product label and a qualified professional.
Frequently asked questions
Does this work for siding?
Yes, if you enter the measured surface area and the product label coverage for that siding or exterior coating. Keep trim and other products separate.
Can I use gallons or liters?
Yes. The existing unit switch converts the entered dimensions, coverage and can capacity. Imperial volume means US gallons.
Does it include primer?
Add primer as a separate product group with its own coverage, coats and can size so it is not mixed with the finish coat.
Method and rule notes
Roomagic’s editorial style profiles use the scoring method described above. Suggestions are subjective and can be changed.
Rule notes reviewed October 21, 2026.