Free · No sign-up · Works offline
Material calculators built for the trades.
Work out exactly how much paint, concrete, tile, drywall or flooring to buy — in seconds, on your phone, right on the job site. Then turn it into a quote for your client.
Choose a calculator
Paint Calculator
Gallons or litres for walls, ceilings and exteriors — with doors, windows and coats.
Calculate →Concrete Calculator
Volume, bags or cement, sand and gravel for slabs, footings, columns and stairs.
Calculate →Tile Calculator
Tiles, boxes, grout and adhesive for floors and walls in any pattern.
Calculate →Drywall Calculator
Sheets, screws, joint compound and tape for walls and ceilings.
Calculate →Flooring Calculator
Packs of laminate, vinyl or hardwood plus underlay and baseboard.
Calculate →Quote Maker
Professional quotes for any trade with your logo, tax and a link your client can accept.
Calculate →Guides — How much paint do I need? Bagged vs ready-mix concrete? Read the guides.
Why tradespeople use QuantoObra
Trade-accurate formulas
The same rules of thumb painters, concrete crews and tilers use — with adjustable waste, coverage and pack sizes.
Private by design
Calculations run in your browser and your measurements stay on your device. Nothing is stored on our servers unless you sign in and choose to save a project or quote. No tracking cookies.
Built for the job site
Big touch targets, works in portrait on any phone, dark mode for basements, and fully offline once loaded.
Shopping lists, not just numbers
Get cans, bags, boxes and sheets to buy — plus a cost estimate when you add prices. Print or copy in one tap.
Imperial & metric
Switch between feet and metres at any time. Your entries convert automatically.
Quotes your clients can accept
Turn any calculation into a professional quote with your logo, tax and a link your client can accept online.
From measurement to signed quote
Add materials straight from any calculator, add your labour rates, and send a branded quote your client can accept from their phone.
Make a quoteIllustrative example with a fictitious company, client and prices.
Example
Harbor Painting Co.
218 Maple Street, Springfield
QUOTE
Q-2026-014
Nov 2, 2026
For
Mrs. Carter
Repaint living room and hallway
| Description | Qty | Unit price | Amount |
|---|---|---|---|
| Surface prep, patching and masking | 1 lump sum | $180.00 | $180.00 |
| Wall painting, 2 coats | 670 ft² | $0.45 | $301.50 |
| Ceiling painting, 2 coats | 260 ft² | $0.38 | $98.80 |
| Paint and supplies | 1 lump sum | $215.00 | $215.00 |
- Subtotal
- $795.30
- Total
- $795.30
Valid until Dec 2, 2026
QuantoObra Pro for professionals
Unlimited quotes with your logo, multi-room projects, saved estimates and branded PDFs. One-time payment — no subscription required.
See Pro