Car Paint Calculator results give gallons of primer, color, pearl and clear from your painted area, coats and coverage, with every product split into paint, activator, and reducer.
Measure the painted panels as rectangles and add them up, or pick a vehicle size. Eastwood’s C-10 pickup worked out to 210 sq ft this way.
Primer, Clear and Pearl Coats
Coverage is the area one gallon covers in a single coat. Use the figure on your can or tech sheet. The presets come from Eastwood product labels.
Color Coverage, Overspray and Mix Ratios
Mix ratios split the sprayable volume into paint, hardener and reducer, so you know what to buy before mixing.
Prices for a Cost Estimate
Enter what you pay per gallon of each product before mixing. The samples are placeholders, not market prices.
Shopping and Mixing List
| Layer | Coats | Mix | Sprayable | Paint | Hardener | Reducer |
|---|---|---|---|---|---|---|
| Primer | 2 | 4:1 | 3.43 gal | 2.74 gal | 0.69 gal | None |
| Base Coat | 2 | Ready to Spray | 1.60 gal | 1.60 gal | None | None |
| Clear Coat | 2 | 2:1 | 3.20 gal | 2.13 gal | 1.07 gal | None |
| Total | 6 | 8.23 gal | 6.48 gal | 1.75 gal | None |
Car Paint Calculator for Primer, Color and Clear
The Car Paint Calculator works out how much primer, color and clear to buy for a respray, and how much hardener and reducer comes with each. It handles base coat and clear, single-stage urethane, and three-stage pearl finishes. DIY painters use it to order the right amount in one go, since running out halfway through a coat is worse than keeping a little extra.
Start with the painted area in square feet or square meters, or pick a vehicle size, then set the number of color coats. The panels below set primer, clear and pearl coats, the coverage of each product, mix ratios and prices. Coverage can be entered as square feet per gallon or square meters per liter.
Measuring the Car the Eastwood Way
Eastwood’s paint quantity guide measures the body in large rectangles, rounded up to the nearest foot. For its Chevy C-10 pickup, the bedsides, lower cab and fenders, hood, roof, cab back and both sides of the tailgate came to 210 square feet. The calculator’s Regular-Cab Pickup preset uses that same figure.
Door jambs, trunk jambs and under-hood edges are not in that total. A color change usually needs them painted, and Learn Auto Body and Paint says jambs usually take another quart or two of sprayable base. Add those areas to the square footage rather than guessing at the end.
The Coverage Formula for Each Layer
Every layer uses the same arithmetic, run separately for primer, color, pearl and clear. The area times the number of coats, plus your overage, is divided by how much one gallon covers in one coat. It is the same formula Eastwood walks through in its guide.
$$\text{Gallons} = \frac{\text{Area} \times \text{Coats} \times (1 + \text{Overage})}{\text{Coverage per gallon}}$$
Eastwood says many painters mix 10 to 20 percent extra for spills, reshoots and touch-ups, and the calculator defaults to 20 percent. For the C-10, two coats of a 300 sq ft per gallon base works out to 1.68 gallons. Three coats of a 150 sq ft per gallon clear come to 5.04 gallons, three times the color.
The coverage number is the one printed on your can or tech sheet, and it changes a lot between products. Eastwood lists its 3:1 single stage at about 125 sq ft per gallon, its 4:1 base at about 160, and its ready-to-spray base at about 300. Pick the wrong one and the order can be off by more than half.
Mixed Gallons or Gallons in the Can?
A reader under Eastwood’s guide asked whether its 5.04 gallons of clear meant product or reduced material, and the answer changes the order. Eastwood states that its coverage figures are for a coat of fully catalyzed paint, which means the paint after mixing. The Car Paint Calculator treats coverage that way by default, then splits the sprayable total back into the separate products.
$$\text{Paint to buy} = \text{Sprayable} \times \frac{\text{Paint parts}}{\text{Total parts}}$$
So the C-10’s 5.04 gallons of sprayable 2:1 clear is about 3.36 gallons of clear plus 1.68 gallons of hardener. If your tech sheet quotes coverage for paint before mixing, switch the Coverage Figures Are Per menu. The calculator then grows the sprayable volume by the mix ratio instead.
Mix ratios matter most for base coat. Many bases reduce 1:1, so the thread on ThirdGen describes one gallon of base becoming two gallons sprayable. The Mix Ratio menus cover ready-to-spray, paint-to-reducer, paint-to-hardener and three-part ratios for each layer.
Single Stage and Three-Stage Pearl
Single-stage urethane carries its own gloss, so the Car Paint Calculator drops the clear layer and puts hardener and reducer on the color itself. It lays down heavier than base, which is why Eastwood’s single-stage coverage is lower. Expect more gallons of color and none of clear.
Tri-coat pearl adds a translucent mid-coat between the ground color and the clear. The calculator gives that layer its own coats and coverage, and the hero result lists the pearl gallons beside the ground color. Because the final color depends on how many mid-coats go on, the calculator’s alert suggests spraying a test panel first and keeping that count the same on every panel.
Turning Gallons Into a Shopping List
The hero result rounds color up to real can sizes, such as 2 gallons or 1 gallon plus 1 quart. The shopping table then lists every layer with its coats, mix ratio, sprayable volume, paint, hardener and reducer. The totals row is what you carry to the counter.
Buy all the color at once from the same batch. A member of the For B Bodies Only Mopar forum recommends intermixing two gallons of base before spraying so the shade cannot vary between cans. Clear is different, since Learn Auto Body and Paint warns never to mix a whole clear kit at once when you may not need it all.
The cost estimate multiplies each product by the price you enter per gallon before mixing. The sample prices in the tool are placeholders, so replace them with your supplier’s prices. Tape, sandpaper, masking paper and gun supplies are not included.
What Painters Ask Before Ordering
How many gallons of paint does it take to paint a car?
For a midsize sedan at 200 square feet, two coats of a ready-to-spray base at 300 sq ft per gallon come to about 1.6 gallons with 20 percent extra. A base that covers only 160 sq ft per gallon needs about 3 gallons sprayable for the same job. That spread is why the coverage figure on your can matters more than the size of the car.
Why do I need more clear than color?
Clear often goes on in more coats and covers less area per gallon than a ready-to-spray base. Eastwood suggests three or more clear coats for a show finish, which is why its C-10 example needs 5.04 gallons of clear against 1.68 of color. The owner of Eastwood’s featured 1968 Charger used three gallons of color and five of clear.
Will one gallon of base coat be enough?
Often it is, once it is reduced. At a 1:1 reduction, one gallon in the can becomes two gallons sprayable, which covers the 1.6-gallon sedan estimate above. A truck, or a color change that adds the jambs, can push past it, so run your own area and coverage through the Car Paint Calculator before ordering.