# JoistCalc

> Free construction material calculators — concrete, gravel, lumber, drywall,
> paint, roofing, plumbing, electrical, HVAC, flooring, insulation and joists.
> Every calculator publishes the formula it uses on the page, alongside
> reference tables, a worked example and the cases where the estimate breaks
> down. No account, no app, nothing uploaded — saved work stays in the
> visitor's own browser.

Figures are estimates for planning. Local building codes, manufacturer
instructions and tested product ratings govern; see the disclaimer.

## Calculators

- [Concrete Calculator](https://www.joistcalc.com/calculators/concrete): Calculate concrete volume in cubic yards and bags for slabs, footings, round columns, and stairs. Free, accurate, and built for the jobsite.
- [Gravel Calculator](https://www.joistcalc.com/calculators/gravel): Calculate how many tons of gravel, crushed stone, sand, or topsoil you need for a driveway, base, or fill job.
- [Lumber Calculator](https://www.joistcalc.com/calculators/lumber): Calculate board footage for lumber orders and stud count for framing a wall, on 16" or 24" centers.
- [Drywall Calculator](https://www.joistcalc.com/calculators/drywall): Calculate drywall sheets, screws, and joint compound needed for a room by wall and ceiling area.
- [Paint Calculator](https://www.joistcalc.com/calculators/paint): Calculate how many gallons of paint you need for a room based on wall area, number of coats, and coverage rate.
- [Roofing Calculator](https://www.joistcalc.com/calculators/roofing): Calculate roofing squares and shingle bundles needed, adjusted for roof pitch.
- [Plumbing Calculator](https://www.joistcalc.com/calculators/plumbing): Calculate water volume in a pipe run, or the drain slope and total fall needed for a waste line.
- [Electrical Calculator](https://www.joistcalc.com/calculators/electrical): Calculate voltage drop for a circuit run, or estimate minimum wire gauge and breaker size for a residential branch circuit.
- [HVAC Calculator](https://www.joistcalc.com/calculators/hvac): Estimate room cooling/heating BTU load, or recommended round duct diameter for a given airflow.
- [Tile & Flooring Calculator](https://www.joistcalc.com/calculators/flooring): Calculate square footage and box count needed for tile, laminate, vinyl plank, or hardwood flooring.
- [Insulation Calculator](https://www.joistcalc.com/calculators/insulation): Calculate batt/roll insulation bags needed, or spray foam board feet and kits needed for a given area and thickness.
- [Floor & Ceiling Joist Calculator](https://www.joistcalc.com/calculators/joists): Calculate floor and ceiling joist count and board footage from span, on-center spacing, and joist size.

## About this site

- [All calculators](https://www.joistcalc.com/calculators/)
- [About](https://www.joistcalc.com/about): JoistCalc builds free, accurate material calculators for concrete, gravel, lumber, drywall, paint, and roofing — no sign-up required.
- [Contact](https://www.joistcalc.com/contact): Get in touch with JoistCalc — questions, bug reports, and calculator requests.
- [Donate](https://www.joistcalc.com/donate): Support the development of new free construction calculators at JoistCalc.
- [Privacy Policy](https://www.joistcalc.com/privacy-policy): Privacy Policy for JoistCalc — how we handle cookies, advertising, and data.
- [Terms of Use](https://www.joistcalc.com/terms-of-use): Terms of Use for JoistCalc — the conditions for using these free construction calculators, and the limits on what their estimates can be relied on for.
- [Disclaimer](https://www.joistcalc.com/disclaimer): Disclaimer for JoistCalc — estimates only, not professional or engineering advice.
- [Your saved calculations & job estimates](https://www.joistcalc.com/projects): Group saved calculations into a named project and see a total material cost and markup estimate for the job — stored only in this browser.

## Languages

Every page above exists in English, Spanish, French, German, Portuguese and
Korean. Locale URLs are prefixed (/es/, /fr/, /de/, /pt/, /ko/) and declared
via hreflang on each page and in https://www.joistcalc.com/sitemap.xml.