THE PAINT OFFER COMPARISON GUIDE
Compare the order.
Keep the job constant.
A tin price is only one part of a paint quote. Coverage and pack size change the number of whole tins needed for the same area and coats. This guide keeps those steps visible.
Start with one net painted area
Use the surface area that will actually receive this paint, before multiplying by coats. If you measured several walls and deducted unpainted openings, carry the resulting net square metres into this comparison. The main paint planner can combine those measured rectangles.
One coat count applies to every offer. The comparison is appropriate to that shared assumption. If the products you are considering call for different coat counts or separate primers, check those requirements in separate plans instead of pretending the jobs are the same.
Enter the coverage for each offer
Coverage here means square metres per litre for one coat. It is an input from the supplier or product information, not a value chosen by Coatcount. The calculator divides the coated area by that input:
No extra percentage is added automatically. This tool also does not infer surface preparation, absorption, application loss or real coverage from a paint name. Confirm the product assumptions you want to use.
Round upward to the one tin size you entered
Each offer has one pack volume. Divide the litres needed by that tin volume, then round upward to complete tins:
Purchased litres = whole tins × tin volume
Estimated surplus = purchased litres − litres needed
These formulas do not optimise a mixture of smaller and larger tins. To compare different pack sizes for the same product, enter them as separate offers with their own quoted prices.
The estimated surplus is a difference between modelled volumes. It does not promise usable paint left over after the job, because this comparison does not model every source of real paint use.
A hypothetical 60 m², two-coat comparison
The coated area is 60 × 2 = 120 m²-coats. Apply the three hypothetical coverage figures separately:
| Offer | Coverage | Tin volume | Quoted tin price |
|---|---|---|---|
| Hypothetical A | 12 m²/L/coat | 4 L | A$60 |
| Hypothetical B | 10 m²/L/coat | 5 L | A$65 |
| Hypothetical C | 15 m²/L/coat | 4 L | A$70 |
| Offer | Litres needed | Whole tins | Purchased / surplus | Paint total |
|---|---|---|---|---|
| A | 120 ÷ 12 = 10 L | ceil(10 ÷ 4) = 3 | 12 L / 2 L | 3 × A$60 = A$180 |
| B | 120 ÷ 10 = 12 L | ceil(12 ÷ 5) = 3 | 15 L / 3 L | 3 × A$65 = A$195 |
| C | 120 ÷ 15 = 8 L | ceil(8 ÷ 4) = 2 | 8 L / 0 L | 2 × A$70 = A$140 |
In these inputs, C has the highest price per tin and the lowest whole-order paint total. That follows from its entered coverage and tin volume. It says nothing about whether the hypothetical products would have the same finish, quality, durability or preparation needs.
Keep decimal boundaries exact
If 0.3 m² needs one coat at an entered coverage of 0.1 m²/L/coat, the required amount is exactly 3 L. With a 3 L tin, that is exactly one tin and zero modelled surplus. Entering 0.300000001 m² under the same assumptions produces a requirement slightly above 3 L, so the mathematical order becomes two tins.
The calculator accepts up to nine decimal places for area, coverage and volume. It keeps those entered decimals exact for the whole-tin calculation. Litres in the table are displayed to three decimal places with an approximation mark when necessary; that display rounding is never fed back into the tin count. Tin prices accept two decimal places in Australian dollars and quoted totals use exact cents.
This arithmetic precision does not mean a physical area or coverage rating is known to nine decimal places. Use the precision appropriate to the measurements and supplier information you have.
Blank quotes and equal totals
You can leave a price blank and still compare quantities. The result will say “Not quoted” for that paint total. A lowest-cost message compares only the offers with prices and states how many offers were priced. If just one offer is priced, the tool shows that quote without declaring it the cheapest.
Equal quoted totals are shown as a tie. A quoted price of zero is accepted as your entered number; the tool does not invent a free offer or fetch any supplier prices.
Compare like purchase terms, then check suitability
- Confirm each coverage figure refers to one coat and the intended product.
- Use the actual tin volume and a quoted price for that whole tin.
- Keep tax included or excluded on the same basis across quotes.
- Check product suitability, finish, preparation and required coats separately.
- Budget for primer, delivery, tools and labour separately; none is added here.
The shared coat-count input accepts whole numbers from 1 to 1,000 as a calculator limit, not a coating recommendation. Up to four offers can be compared in one plan.
Keep the comparison you checked
Download the text comparison or print the results and volume diagram. The calculator code keeps input values in the current page and does not save them automatically. Refreshing clears the plan. Read the privacy information for hosting, traffic measurement, advertising and email correspondence.
For a calculation correction, use the contact page or email the public forwarding address coatcount.visa722@aleeas.com. Include the figures you entered so the arithmetic can be checked.