Construction & DIY Calculators
Every calculator shows its formula, a worked example and its sources.
Embed any calculator on your site · Open data: Florida contractor licenses by county
Concrete
- Concrete Slab Calculator (Cubic Yards & Bags)
- Concrete Column & Sonotube Calculator
- Concrete Footing Calculator (Continuous Wall Footings)
- Rebar Calculator for a Slab (Bars, Sticks, Lap Splices & Weight)
- Concrete Steps Calculator (Cubic Yards, Bags, Risers & Landing)
- Epoxy Floor Calculator (Gallons and Kits by Mils and Solids)
Interior
- Paint Calculator (Gallons for Walls)
- Drywall Calculator (Sheets Needed)
- Flooring & Tile Calculator (Square Feet & Boxes)
- Tile Grout Calculator (Pounds and Bags of Grout)
- Thinset Calculator (Bags of Thin-Set Mortar by Trowel Size)
- Self-Leveling Concrete Calculator (Bags of Floor Leveler)
- Caulk Calculator (Tubes of Caulk or Sealant per Linear Foot)
Exterior
- Roofing Calculator (Squares, Bundles & Pitch Factor)
- Deck Board Calculator
- Fence Calculator (Posts, Rails & Pickets)
- Gutter & Downspout Size Calculator (Roof Runoff, Gutter Capacity, Number of Downspouts)
- Attic Ventilation Calculator (Net Free Area, Ridge & Soffit Vents)
- Stucco Calculator (Bags of Base and Finish Coat)
Landscape
- Mulch, Gravel & Topsoil Calculator (Cubic Yards)
- Paver Calculator (Pavers, Base Gravel & Sand)
- Sod Calculator (Square Feet, Pieces & Pallets)
- Retaining Wall Block Calculator (Blocks, Caps, Base Gravel & Drainage Rock)
Electrical
- Wire Size & Voltage Drop Calculator (AWG, Copper/Aluminum)
- Generator Size Calculator (Running & Starting Watts for Your House)
- Electrical Box Fill Calculator (NEC 314.16)
- Conduit Fill Calculator (NEC Chapter 9, EMT and PVC)
- Wire Size Calculator (Ampacity, 125% Rule and Voltage Drop)
HVAC
- Room AC BTU Calculator (ENERGY STAR Sizing)
- Dehumidifier Size Calculator (Pints per Day by Room Size)
Energy
- Insulation R-Value Thickness Calculator
- Solar Panel Calculator (How Many Panels Do I Need?)
- Appliance Energy Cost Calculator (kWh and $ per Year)
Pool
- Pool Volume Calculator: Rectangular (Gallons)
- Pool Volume Calculator: Round / Above-Ground (Gallons)
- Pool Volume Calculator: Oval (Gallons)
- Pool Salt Calculator (Pounds of Salt for a Saltwater Pool)
- Pool Liquid Chlorine Calculator (Ounces to Raise Free Chlorine)
- Pool Alkalinity Calculator (Baking Soda to Raise, Muriatic Acid to Lower)
- Pool Stabilizer (Cyanuric Acid) Calculator: How Much to Add or Drain
- Pool Calcium Hardness Calculator (Calcium Chloride to Raise, Water to Drain to Lower)
- Pool LSI Calculator (Langelier Saturation Index / Water Balance)
- Pool Heater Size Calculator (BTU for Gas Heaters and Heat Pumps)
- Pool Turnover Rate & Pump GPM Calculator
Lumber
Paving
Framing
- Stair Stringer Calculator (Risers, Treads & Stringer Length)
- Rafter Length Calculator (From Run and Roof Pitch)
- Wall Stud Calculator (Studs & Plates for a Framed Wall)
Masonry
- Brick Calculator (How Many Bricks for a Wall)
- Concrete Block (CMU) Calculator
- Mortar Calculator for Brick and Block (Cubic Feet & Bags)
Septic
Plumbing
- Tankless Water Heater Size Calculator (GPM, Temperature Rise, BTU & kW)
- Water Softener Size Calculator (Grains per Day and Capacity)
- Well Pressure Tank Size Calculator (Drawdown and Pump Run Time)
FAQ
Are these calculators free?
Yes. Every calculator is free to use, and you can embed any of them on your own site with one iframe as long as you keep the visible credit link.
Where do the formulas come from?
Formulas are standard geometry plus published constants, and each calculator page shows its formula, a worked example and its sources.
Are the results professional advice?
No. Results are estimates, not engineering, code-compliance or professional advice. Verify quantities with your supplier and code requirements with your local building department.
Are my inputs sent anywhere?
No. Calculations run in your browser and no calculator inputs are sent to a server.
What if my product uses a different coverage or density?
Defaults that vary by product, such as paint coverage, gravel or asphalt density and bundles per square, are editable placeholders. Use the figure on your product label or from your supplier.