Math for any
project.
Fast, dead-simple calculators for what you actually buy and install — pro or DIY. No signup, no popups, works on a 4G phone with one bar.
Material calculators for any project around the house — concrete bags or yards for slabs, drywall sheets for a remodel, paint gallons by room, mulch and gravel by the yard, sod pallets, deck stain, fence posts, tile, and roofing shingles. Get the right amount the first time so you're not making a second trip to Home Depot.
Pro-grade calculators grouped by trade — carpentry cut lists and board feet, masonry brick counts and siding squares, electrical voltage drop and conduit fill to NEC, plumbing pipe slope and water capacity, HVAC BTU sizing and duct CFM. Built for contractors, electricians, framers, plumbers, and anyone bidding a job.
Quick money math — mortgage payments with full amortization, car loan payments factoring in down payment and trade-in, personal loan payoff math, and restaurant tips with bill split. Skip the bank's overcomplicated calculator — these give you the real number in three inputs.
Built the calculators? Buy the bundles. Excel workbooks that take what you measured here and turn it into a full takeoff, parts list, and customer quote — or, for the Garage Ledger Vault, a complete project-car build tracker with dashboard and ROI math.
All 6 trade toolkits in one Excel bundle — Roofing, Plumbing, Electrical, HVAC, Concrete, Framing. Every estimate, takeoff, and quote sheet across the trades.
- Save $137 vs. buying all 6 toolkits separately ($234 → $97)
- Single .zip with 6 fully-formatted .xlsx workbooks
- Works in Excel, Google Sheets, LibreOffice, Apple Numbers
All 6 project-car build trackers — Pro + LS Swap, Cummins Swap, Overland, Restomod, Track Build. Spend log + parts inventory + dashboard + ROI for every kind of build.
- Save $205 vs. buying all 6 separately ($334 → $129)
- 5 build-type variants with pre-filled categories + milestone phases
- DIY hours × your shop rate baked into the ROI sale-comp sheet
What is ProjectCalc?
ProjectCalc is a free collection of 73calculators for construction, home improvement, and DIY projects. Whether you're a contractor sizing a job or a homeowner figuring out how much paint to buy, every calculator gives you the answer in one click — with the math shown so you can double-check.
No signup, no popups, no email capture, no AI chatbot interrupting you. Just calculators that work, on any phone, on any connection. The calculators run entirely in your browser — your inputs never leave the page.
Built for both pros and homeowners
Every calculator gives you the headline answer (sheets, bundles, gallons, yards, BTUs) plus the supporting math so you can sanity-check the result. Technical inputs include plain-English tooltips for things like roof pitch, wire gauge (AWG), and R-value — useful if it's your first time spec'ing the job, ignored if you already know.
Common questions per calculator answer the things people actually search for: how much things cost, how to measure correctly, what to buy at Home Depot vs the lumber yard, and the rules of thumb pros use.