A FRESH COAT. A CLEARER PLAN.
Paint calculator.
Less guessing.
Measure the walls. Read the tin. Compare what you actually need to buy, with room for one more coat.
Your coverage. Your prices. · No account · Free01 / MEASURE THE MAKEOVER
Give every wall a place.
All surfaces share the entered coverage and coat count. Compare A and B separately by default; use separate plans if their coverage differs. Ceilings, trim and primer are excluded.
Valid edits save in this browser when storage is available.
A shared link includes an editable copy of your entire plan.
A PLAN, BEFORE THE FIRST BRUSHSTROKE
The label matters
more than the average.
Texture, surface condition and the finish you need affect paint usage. The default 10 m²/L and two coats are an example, not a product promise.
Sherwin-Williams’ measuring guidance explains subtracting large doors and windows and checking your selected paint’s label. Follow its preparation and application instructions.
A 3.6 × 4.2 m room with 2.4 m walls has 37.44 m² of wall area. Subtract one 0.9 × 2.1 m door and one 1.2 × 1.2 m window: 34.11 m² remains. Two coats at 10 m²/L need 6.822 L before any extra. That means three 2.5 L tins or two 5 L tins.
A 3 × 5 m room with 2.5 m walls and no openings has 40 m² to paint. Two coats at 10 m²/L need 8 L. If the same paint costs $40 for 5 L (A) or $27 for 3 L (B), buying one of each gives exactly 8 L for $67. A-only costs $80 for 10 L; B-only costs $81 for 9 L. The combination saves $13 against the cheaper single-size choice.
With a third coat, 12 L is needed. Two A tins plus one B cost $107 for 13 L; four B tins cost $108 for exactly 12 L. The least expensive purchase can leave more paint over.
What does this tool include?
Vertical walls only. A rectangular room uses 2 × (length + width) × height; a single wall uses width × height. We subtract measured door and window areas, multiply by coats, divide by coverage per coat and add your optional percentage. Existing usable matching paint is deducted before whole tins are counted.
Do I need a separate plan for every color?
Both separate options use the same entered coverage and coats. If the products differ in coverage or required coats, run separate plans. Only enable combined purchasing when both tins contain the same product, color and finish. Every surface in a plan uses one selected paint; this is not a multi-color project editor. The preview colors are decorative illustrations and do not model real paint colors, lighting, coverage or whether one color will hide another.
What if openings have different sizes?
Each room or wall supports one repeated door size and one repeated window size. For mixed opening sizes, split the room into individual wall entries or use the average opening area expressed as width × height. Check total areas carefully. The sketch does not position openings.
Is a bigger tin always cheaper?
Not for every project. We round each option up to whole tins and compare the resulting total cost, showing the paint left over. By default, we compare A-only and B-only purchases. With your same-paint confirmation, we also find the lowest-cost whole-tin combination of the two sizes. At equal cost we choose fewer tins, then less leftover. The winner may use only one size. We do not search shops or account for discounts. Leftover estimates include any unused paint you already own.
Why show one extra coat?
It helps you see how another coat changes paint volume and shopping quantities. It is a scenario, not a claim that an extra coat is required. Follow your product’s instructions and assess the actual surface.
Can I save and share the plan?
Valid changes save locally if your browser permits storage. A shared link includes room names, dimensions, prices and other inputs; anyone with it can read and edit a copy. The downloadable text list includes calculations, both separate options, any enabled same-paint combination, the extra-coat comparison and assumptions. Old saved plans open with combined purchasing off.