Paint Calculator の使い方 — paint do I need for a room?
Calculate paint litres from surface area, coats, product coverage and a sensible allowance for touch-ups and substrate variation.
Paint volume = net painted area × number of coats ÷ stated coverage per litre, with any chosen allowance applied.
Calculate paint litres from surface area, coats, product coverage and a sensible allowance for touch-ups and substrate variation. The linked Sellible tool keeps the fields, units and output together so the assumptions can be reviewed before the result is used.
- 1
Measure wall and ceiling surfaces separately.
- 2
Subtract substantial doors and windows.
- 3
Use the product coverage and planned coat count.
Example values and result
These values demonstrate the method; replace them with measurements, rates or file details that match the real task.
- Wall area after openings
- 54 m²
- Number of coats
- 2
- Coverage
- 12 m²/L
- Base requirement
- 9 litres
The example needs about 9 litres before any extra allowance. Porous surfaces, colour changes and application method can increase consumption.
精度と実用上の注意
- Include primer or mist coat as a separate product.
- Check surface porosity and colour change.
- Round to available tin sizes without excessive surplus.
Common mistakes
- Counting floor area as wall area.
- Using one-coat coverage for a two-coat specification.
- Assuming every paint has the same spreading rate.
A free account makes repeat tasks simpler
Email-link sign-in keeps file jobs, downloads, support and usage available across devices. Browser calculators remain free.
よくある質問
Is Paint Calculator free?
Yes. This calculator or browser utility is free and does not use processing credits.
Can I use this guide and Paint Calculator on a phone?
Yes. The guide, inputs, results and calls to action are responsive and keyboard accessible on current phones, tablets and desktop browsers.
Should I order or make a decision from the estimate alone?
No. Include primer or mist coat as a separate product. Check surface porosity and colour change. The calculation is a planning aid rather than professional or regulatory approval.
How should I check the result?
Keep the source values and units visible, compare the result with supplier or project information, and retain enough precision until the final purchasing or reporting step.