Construction & Home Improvement
Calculators
BuildMate combines 53 construction calculators with AI project planning, material estimates, cost planning, shopping lists and project guides — free, no signup.
AI Project Planner
Describe your project. Get a complete plan.
Type something like “I want to build a 20 × 20 concrete patio.” BuildMate asks only the questions it needs, then builds your materials list, planning cost range, tools, timeline, step-by-step plan and shopping list — ready to print or save.
Construction calculators
53 formulas with the math shown
AI project planning
Describe it in plain English
Material estimates
Quantities with waste allowance
Cost planning
Transparent 2026 USD ranges
Shopping lists
Grouped, printable, copyable
Project guides
Step-by-step how-tos
Concrete, block, lumber, drywall and more
Quantity calculators with the formula shown and 2026 USA prices in USD.
Concrete Calculator
Enter your slab length, width and thickness to get cubic yards, bag counts and a 10% waste allowance instantly. Prices below are 2026 USA averages in USD.
Open calculatorBlock Calculator
Enter wall length and height to get block counts, mortar bags and core fill. Standard 8×8×16 CMU covers 1.125 square feet of wall face including the joint.
Open calculatorLumber Calculator
Enter wall length, height and stud spacing to get stud counts, plate stock and board feet with a 10% cut-waste allowance built in.
Open calculatorDrywall Calculator
Enter room dimensions to get sheet counts for 4×8 and 4×12 panels, plus joint compound, tape and screws with a 10% waste allowance.
Open calculatorRebar Calculator
Enter slab dimensions and grid spacing to get bar counts in both directions, total linear feet with laps, and the number of 20 ft sticks to order.
Open calculatorGravel Calculator
Enter area and depth to get cubic yards and tons of crushed stone. Most gravel weighs about 1.4 tons per cubic yard once compacted.
Open calculatorDeck Calculator
Enter deck length, width and board size to get board counts, joist counts at your chosen spacing, and fastener quantities with 10% cut waste.
Open calculatorFence Calculator
Enter fence length, post spacing and picket width to get post, rail and picket counts plus the bags of concrete needed to set each post.
Open calculatorCalculators for the most common projects
A good place to start if you're planning a slab, a roof, a kitchen or a purchase.
Concrete Calculator
Slabs, footings & columns
Mortgage Calculator
Loan, interest, term, tax & insurance
Kitchen Remodel Cost Calculator
Estimate a full kitchen renovation
Roof Calculator
Shingles & underlayment
Remodel and cost planning tools
Cost and finance calculators for the bigger decisions — remodels, roofs, decks and refinancing.
Work out how much to buy
Quantity calculators for paint, tile, flooring, decking and driveways — each with its formula and waste allowance shown.
Paint Calculator
Interior & exterior walls
Tile Calculator
Floor & wall tiles
Flooring Calculator
Hardwood, laminate & vinyl
Mortgage Payment Calculator
P&I + tax + PMI monthly payment
Deck Cost Calculator
Wood or composite decking
Concrete Driveway Cost Calculator
New concrete driveway install
What we last went through
Assumptions and price ranges are re-checked periodically. These pages were the most recent pass.
How-to questions, answered with a calculator
Specific site questions — patio concrete, studs per wall, tiles per bathroom — each with the manual formula worked out step by step.
Concrete & Masonry
How to Calculate Concrete for a 20x20 Patio (Free AI Tool)
Concrete & Masonry
How Much Rebar Do I Need for a Concrete Slab?
Concrete & Masonry
Concrete Block Calculator With Aggregate Breakdown
Concrete & Masonry
How Many Bags of Concrete Mix for Fence Posts?
Concrete & Masonry
Estimate Gravel and Sand Ratio for Cement Mixing
Framing & Carpentry
How Many Studs Do I Need for a 10 Foot Wall?
Framing & Carpentry
Rafter Length Calculator for a Gable Roof
Framing & Carpentry
How Much Lumber to Build a Backyard Deck
Framing & Carpentry
Drywall Sheet Calculator With Wastage Percentage
Describe your project.
Get a full plan.
"I want to build a 20×20 concrete patio." — BuildMate AI returns materials, quantities, labor cost, timeline, a shopping list and a step-by-step guide.
Try the AI Estimator▸ prompt: 20×20 ft concrete patio, 4" thick
◂ concrete: 5.43 yd³ (with 10% waste)
◂ rebar: 320 ft of #4 @ 16" O.C.
◂ gravel base: 2.5 yd³ of ¾" crushed
◂ labor: ~24 hrs · 2 workers
◂ est. cost: $1,850 – $2,400
◂ timeline: 3 days (form → pour → cure)
✓ Ready to export as PDF
Learn to build anything
Beginner-friendly walkthroughs — from pouring a slab to renovating a full kitchen — with the math shown.
How to Install a Pre-Hung Interior Door
Shimming, plumbing and hanging a pre-hung door so it latches cleanly and stays where you leave it.
How to Frame a Basement Wall
Moisture control, wall placement, bottom plates on concrete and the framing sequence for a basement finish that lasts.
How to Replace a Kitchen Faucet
A 60–90 minute swap done properly: shutoffs, the basin wrench problem, supply lines and leak testing.
How to Add Attic Insulation the Right Way
Air sealing first, baffles at the eaves, correct R-value by climate zone and how to add blown-in over existing batts.
How to Calculate Concrete Volume for Columns and Footings
Cylinder and box volume math for deck footings, fence posts and pier columns — with a full worked example.
The Retaining Wall Block Calculator Guide: Standard Sizes & Estimating Rules
Count blocks, caps, base gravel and drainage stone for a segmental retaining wall — including the buried base course.
Smart reads for your next project
Cost breakdowns, how-to explainers and planning advice from BuildMate Guides.
Cost Per Square Foot by Project Type (USA 2026 Reference)
One table for every major renovation: installed price per square foot for additions, kitchens, baths, basements, flooring, paint, roofing and siding.
Labor vs Material Cost Split by Trade (USA 2026)
What share of your bill is labor on 18 common trades — and what that means for DIY savings, supplied materials and negotiating a quote.
Home Addition Cost in the USA 2026: Room-by-Room Breakdown
What a bump-out, a full room addition, a second story and a sunroom cost in 2026 — with the foundation, framing, MEP and finish line items behind the number.
Transparent methods, documented assumptions
Every number on this site can be traced back to a formula and a stated assumption.
1. Standard trade formulas
Quantities come from published trade math — area, volume, coverage rates, on-centre spacing. The formula is printed on the page so you can check it by hand.
2. Documented assumptions
Thicknesses, coverage rates, waste allowances and unit conversions are stated, not hidden. Where a value is adjustable, you can change it.
3. Published price ranges
Cost tools use national low/high price ranges for materials and labor, then apply a state adjustment factor. They are planning ranges, not quotes.
4. Ranges, not false precision
Cost outputs are shown as a range because bids vary with site access, season and finish level. A single exact number would be misleading.
Estimates are for planning only and don't replace a licensed contractor's on-site bid. Read our full methodology or the disclaimer.
Built like a pro tool. Free like a public utility.
No invented statistics, no fake reviewers — just documented methods you can check.
Formula shown, every time
Each calculator prints the formula, the inputs it used and the waste allowance applied, so you can verify the result yourself.
Assumptions written down
Coverage rates, thicknesses, price ranges and state adjustment factors are documented on our methodology page.
Planning estimates, clearly labelled
We don't present estimates as quotes or as engineering design, and we say when to bring in a licensed professional.
Private by default
No login required. Calculator inputs stay in your browser. Quote request forms are opt-in only.
No paywalls, no dark patterns
Every calculator, guide and AI estimate is free, with no credit card and no forced signup.
Corrections welcome
If a number looks wrong, tell us — our corrections policy explains how we log and publish fixes.
Every corner of the house
From the foundation to the roof and everything in between.
Frequently asked questions
Everything you'd want to ask before trusting a number on this site.
New calculators + 2026 pricing, monthly.
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Ready to build something great?
Pick a calculator, see the formula, and plan your project with numbers you can check.