Estimating guide

Painting Estimate Spreadsheet: Formulas and Template

A spreadsheet is the most common way small painters estimate. Here is how to set one up with formulas that get the math right, plus the honest trade-offs against estimating software.

The layout

One row per room. Put your rates in a few cells at the top so every formula uses the same numbers.

Cell	Setting	Example
J1	Coats	2
J2	Coverage (sq ft per gallon)	350
J3	Wall labor ($ per sq ft)	2.25
J4	Ceiling labor ($ per sq ft)	1.50
J5	Paint ($ per gallon)	52

Columns A to H, starting on row 2:

A	B	C	D	E	F	G	H
Room	Length	Width	Height	Doors	Windows	Wall sq ft	Ceiling sq ft

Formulas to copy

These work in both Excel and Google Sheets. Enter them in row 2, then fill down.

Wall sq ft (G2): =MAX(0, 2*(B2+C2)*D2 - E2*21 - F2*15) Ceiling sq ft (H2): =B2*C2 (leave blank if the ceiling isn't painted)

Then the totals, below your rooms:

Total walls: =SUM(G2:G20) Total ceilings: =SUM(H2:H20) Wall gallons: =ROUNDUP(SUM(G2:G20)*$J$1/$J$2, 0) Ceiling gallons: =ROUNDUP(SUM(H2:H20)*$J$1/$J$2, 0) Labor: =SUM(G2:G20)*$J$3 + SUM(H2:H20)*$J$4 Paint: =(wall gallons + ceiling gallons)*$J$5

Round up the total, not each room. If you round gallons per room, three rooms that each need 1.2 gallons become 6 gallons instead of 4. Add up the area first, then round. Keep walls and ceilings separate, since they're usually different paints.

Worked example

Room	L × W × H	Doors	Windows	Walls	Ceiling
Living room	18 × 14 × 9	2	3	489	252
Primary bedroom	14 × 12 × 8	2	2	344	—
Hallway	20 × 4 × 8	4	0	300	80
Total				1,133	332

Wall gallons: ROUNDUP(1,133 × 2 ÷ 350) = ROUNDUP(6.5) = 7 Ceiling gallons: ROUNDUP(332 × 2 ÷ 350) = ROUNDUP(1.9) = 2 Labor: 1,133 × $2.25 + 332 × $1.50 = $3,047.25 Paint: 9 gallons × $52 = $468.00

Spreadsheet vs. software

	Spreadsheet	Field-service software	Free estimator (Coatwise)
Cost	Free or included	Monthly subscription	Free
Setup	You build and maintain the formulas	Onboarding and setup time	None
Client-ready document	You design it yourself	Yes	Yes, PDF with logo and signature line
Errors	A broken formula can go unnoticed	Low	Low
Scheduling, invoicing, CRM	Separate tools	Included	Not included
Best for	People who like to customize everything	Busy companies with several crews	Solo painters and small crews who want fast, clean estimates

Common spreadsheet mistakes

Rounding gallons room by room instead of on the total.
Typing rates directly into formulas, so one price change means editing every cell.
Forgetting to subtract doors and windows, or subtracting them twice.
Sending the raw spreadsheet to the client instead of a clean estimate with scope and terms.

Skip the formulas: enter your rooms and get the same math as a client-ready PDF.

Open the estimator