Hammer CalculatorConstruction calculators for faster, cleaner estimates.
Convert jobsite dimensions into material quantities, coverage, and cost checks for concrete, framing, roofing, painting, landscaping, and more.
Sample estimate
12' x 16' concrete slab
- Area
- 192 sq ft
- Concrete
- 2.4 yd³
- Bags
- 109
- Waste
- 10%
Quick Unit Converter
Convert between common construction units — length, area, volume, and weight — right from the homepage.
Browse by Trade
Pick a trade category first, then drill into the calculators available for that type of project.
Who It's For
Same calculators, different jobs — built to be useful whether you're picking up a trowel or writing a bid.
Homeowners & DIYers
Get material counts and gallons/bags you can actually buy at the store, without guessing at waste factor or square footage math.
Contractors & Tradespeople
Ballpark a bid fast, then edit the pricing to match your own suppliers — every calculator shows a cost comparison, not just a raw quantity.
Renovators & Project Planners
Compare material options side by side — bags vs. delivery, quart vs. bucket — before you commit to an order.
Why Hammer Calculator
No catch — just fast, accurate estimates you can act on.
100% Free
Every calculator is free to use — no account, no paywall, no watermarked results.
Editable Local Pricing
Default prices are a starting point. Punch in your own supplier's rates and the cost comparison updates instantly.
Built for Accuracy
Formulas use the same waste factors and yield tables contractors use on real job sites, not rounded rules of thumb.
Works Anywhere
Pull it up on your phone at the store or the job site — every calculator is fully responsive.
No Signup Required
Jump straight to results. We don't gate calculators behind an account or an email capture.
Cost Comparisons Built In
Every calculator shows which purchase option is actually cheapest, not just a single number.