Construction calculators
that respect your time.
Free, instant, mobile-first. Imperial or metric, auto-detected from your region. No signup, no email, no fluff.
Calculators
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Concrete Calculator
Slabs and cylindrical footings. Cubic yards or m³, plus 80lb / 60lb / 25kg / 20kg bag counts.
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Wall Framing Calculator
Stud counts at 16″ / 24″ on-center (or 400 / 600 mm metric). Includes waste margin.
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Rafters Calculator
Common rafter length from run and pitch, with ridge-board deduction. Imperial X/12 or metric degrees.
Open Calculator -
Baluster Spacing Calculator
Code-compliant even spacing for deck and stair railings. 4″ US / 100 mm UK-EU defaults.
Open Calculator
What you get
- Live
- Calculations update as you type — no "calculate" button.
- Mobile
- Built for phones first. Use it standing in the dust.
- Auto unit
- Imperial in the US, metric everywhere else. Detected from your browser.
- Free
- No signup, no email, no spam. Web is free; the app is $2.99.
Voice input, offline mode, save jobs to a shopping cart, PDF estimates. One-time $2.99 on Google Play.
Get on Google PlayBuilt by builders
VibeCalc started as an Android app for tradespeople doing the same arithmetic on every job: slab volumes, stud counts, rafter lengths, baluster spacing. The web version puts the same formulas in a browser tab.
Concrete by L × W × T or π × r² × h. Studs by length over on-center spacing plus the end stud. Rafters by Pythagoras minus the ridge plumb-cut. Balusters by gap distribution under code limits. The math is real, the formulas are open, the answers update as you type.
Disclaimer
VibeCalc provides free construction calculators for estimation purposes only. Calculations are based on standard construction formulas and do not account for site-specific conditions, local building codes, soil-bearing capacity, environmental factors, or material variations.
These calculators are not a substitute for professional engineering, architectural, or contracting advice. For any load-bearing structure, foundation, roof framing, guardrail, or other safety-critical work, you must consult a licensed structural engineer or qualified contractor and comply with your local building codes and permit requirements.
You are solely responsible for verifying all measurements, material specifications, applicable building codes, and the suitability of any calculator output for your specific project.
To the maximum extent permitted by law, VibeCalc, its operators, contributors, and licensors disclaim all warranties (express or implied) and all liability for any errors, omissions, inaccuracies, property damage, personal injury, financial loss, or other damages arising from or related to use of these calculators or reliance on their output.
By using VibeCalc you acknowledge that you have read, understood, and accepted this disclaimer and that you assume all risk associated with your use of the site and any decisions made based on its output.