Measurement & Materials
Paint area and gallons
Measure wall or ceiling sections, subtract openings and estimate paint containers from coats and the actual product coverage.
Your inputs
Complete the fields for your selected method. Zero means intentionally zero, not unknown. Currency selection labels amounts; it does not convert exchange rates.
How this calculation works
paint gallons = net paintable square feet × coats / coverage per gallon; containers = ceil(gallons / container size)
A quantity estimate from your measurements, not a drawing takeoff, layout optimization, engineering design or code approval. Keep overlapping sections out of the total. Material allowances are your assumptions; supplier package sizes, product coverage and prices must come from the actual product or quote. Optional prices entered as zero are omitted; cost subtotals include only entered prices. Product coverage is per coat and varies with surface condition and application. Use the product label or a job-specific estimate. Primer, different colors or finishes, trim, application loss beyond the supplied coverage, supplies and labor need separate estimates.
What information do I need?
Use records for the same job, equipment or accounting period. Only the fields for your selected entry method are required. An unknown amount is not zero.
Input definitions and where to find them
- Which area information do you have?: Use matching records or an explicitly identified assumption for which area information do you have?. Unknown is not the same as zero.
- Rectangular sections — add each nonoverlapping section once: Use matching records or an explicitly identified assumption for rectangular sections — add each nonoverlapping section once. Unknown is not the same as zero. Used with: Measure rectangular sections.
- Section name: Use matching records or an explicitly identified assumption for section name. Unknown is not the same as zero.
- Section length (ft): Measure this distance. Choose feet, inches or meters beside the field; decimal feet and decimal inches are accepted. Use the feet-and-inches tool to convert fractions if needed.
- Section width (ft): Measure this distance. Choose feet, inches or meters beside the field; decimal feet and decimal inches are accepted. Use the feet-and-inches tool to convert fractions if needed.
- Already measured area (ft²): Enter the measured surface area in the selected unit, not a length. Use net area after deductions only if those deductions will not be entered again. Used with: I already know the area.
- Openings or uncovered area to subtract (ft²): Enter the measured surface area in the selected unit, not a length. Use net area after deductions only if those deductions will not be entered again.
- Number of coats (coats): Use matching records or an explicitly identified assumption for number of coats. Unknown is not the same as zero.
- Product coverage per US gallon per coat (ft² / US gal): Use matching records or an explicitly identified assumption for product coverage per us gallon per coat. Unknown is not the same as zero.
- Container size (US gal/container): Use matching records or an explicitly identified assumption for container size. Unknown is not the same as zero.
- Optional price per container (0 to omit) (selected currency): Use matching records or an explicitly identified assumption for optional price per container (0 to omit). Unknown is not the same as zero.
Use the Where to find this value controls beside the inputs for available work-it-out helpers. Estimates remain your assumptions; a helper does not verify the source figures.
Worked example
Example amounts use US dollars (USD).
Example answer: Net paintable surface is 120.00 ft² for the illustrative inputs below.
Example inputs
- Which area information do you have?: Measure rectangular sections
- Rectangular sections — add each nonoverlapping section once
- Section name: Section 1
- Section length: 12.00 ft
- Section width: 10.00 ft
- Openings or uncovered area to subtract: 0.00 ft²
- Number of coats: 2 coats
- Product coverage per US gallon per coat: 350.00 ft² / US gal
- Container size: 1.00 US gal/container
- Optional price per container (0 to omit): $0.00
- Net paintable surface
- 120.00 ft²
- Calculated paint before container rounding
- 0.6857 US gal
- Whole paint containers
- 1 containers
- Paint purchased after container rounding
- 1.00 US gal
- Paint material cost only
- No price entered
- Enter wall width × wall height for walls; room floor area is not wall area. Include ceilings as separate sections only when the same product and coat count apply.
These illustrative values are not recommended rates or industry averages. Replace every example input with your own figures.
Use the result well
Use the net measured quantity to check a material order or quote. Keep installed area, extra material and purchased quantities separate.
Keep inputs on the same scope and time basis. Calculations retain precision internally; displayed values generally round to two decimal places, with extra precision for very small values and whole-unit rounding where required. Economic comparisons describe your supplied assumptions and do not guarantee future results.
This tool provides business arithmetic. It does not approve engineering designs, establish legal or tax treatment, select equipment or certify safe operating conditions.