Free App

Free construction calculators
for jobsite math.

Concrete, framing, rafters, roofs, balusters, decks, and drywall for carpenters, roofers, and serious DIY. No ads, no signup, and the formula is shown on each calculator page. Use the browser for a quick check, or take the free Android app to the jobsite for offline use, voice input, and material lists.

Free web tools Open calculators No signup. Quick math in the browser. Free Android app Get the Free App Offline, voice input, material lists, PDF export/share.
No ads. No signup. No paywall.
Formulas are shown on each page so you can check them.
Metric or imperial, based on your browser to start.
Built around concrete, framing, rafters, decks, and roofs.

Calculators

Concrete Framing Roofs Decks Stairs Materials Cost

From quick check to material run

Use the website for quick math. When the numbers turn into a material run, open the Android app for offline use, voice input, lists, and PDF export/share.

Choose a calculator
  1. 1

    Pick the job

    Choose concrete, framing, roofs, decks, drywall, stairs, railings, materials, or cost from the list.

  2. 2

    Enter the measurements

    Use the numbers from your tape, notes, or sketch. The fields are large enough for a phone.

  3. 3

    Check the takeoff

    VibeCalc shows counts for waste, packs, boards, bags, bundles, or cost lines when that calculator has them.

  4. 4

    Use the app when the job gets real

    Keep the web version for quick checks. Use Android for offline work, voice input, material lists, and PDF export/share.

Deck and framing shortcuts

If you are laying out railings or studs, these are the quickest places to start.

Open stud calc
Shortcut

Baluster & Spindle Spacing Calculator

Deck baluster, spindle, stair railing, and 4 inch sphere spacing in one place.

 Shortcut

Stud Calc / Wall Stud Calculator

Wall stud counts for 16 inch, 24 inch, 400 mm, and 600 mm layout.

 Shortcut

Baluster Spacing Template

Common 4 ft, 6 ft, 8 ft, 10 ft, stair railing, and metric spindle spacing templates.

 Shortcut

Baluster Spacing Code

4 inch sphere rule, 100 mm metric rule, stair railing gap notes, and calculator links.

Material estimators

Guide

Deck Board Calculator

Board count, rows, and linear footage from deck size, board width, gap, and waste.

 Guide

Drywall Calculator

Sheets of drywall for any wall and ceiling area - 4×8, 4×12, or metric boards, with waste.

 Guide

Concrete Bag Calculator

Quick bag-count estimates for 80lb, 60lb, 25kg, and 20kg concrete bags.

 Guide

Stud Count Calculator

Wall framing stud counts for 16 inch, 24 inch, 400mm, and 600mm spacing.

 Guide

Drywall Sheet Calculator

Sheet counts for 4×8 sheets, 4×10, 4×12, metric boards, and waste.

 Guide

Rafter Length by Pitch Calculator

Rafter length by roof pitch, run, rise, and slope angle.

 Guide

Baluster Spacing Template

Common deck, stair, and spindle layouts with even gap templates.

 Guide

Deck Railing Post Spacing Calculator

Post count and even section spacing before baluster or spindle layout.

 Guide

Baluster Spacing Code

4 inch sphere rule, 100 mm spacing, and code-safe railing gaps.

 Guide

Wall Framing with Doors & Windows

Plan king studs, jack studs, headers, sills, and cripple studs around openings.

 Guide

Ridge Height Calculator

Calculate roof ridge height from span, run, and pitch.

 Guide

Roof Overhang Calculator

Estimate sloped rafter tail length from horizontal eave overhang and pitch.

 Guide

Valley Rafter Calculator

Estimate valley rafter length from run and roof pitch for square roof corners.

 Guide

Rafter Cut Calculator

Plan birdsmouth cuts, plumb cuts, rafter angles, and tail layout before cutting.

 Guide

Lean-To Rafter Calculator

Estimate shed roof and single-slope rafter length from run and pitch.

 Guide

Rake Wall Calculator

Plan gable wall framing, rake wall height changes, and stud layout from roof pitch.

What you get

Live
Numbers change while you type. No extra calculate button.
Mobile
Made for a phone screen, even when you are standing on site.
Auto unit
Starts with imperial in the US and metric most other places, based on your browser.
Cost
Cost tools for the parts VibeCalc can actually count: material, waste, and labor. Not full bid software.
VibeCalc Android app icon
Android App

Take VibeCalc to the jobsite

Offline calculators for Android. Voice input, no signal needed. Free, no ads, no accounts.

Get the Free App Free. Built for Android phones. Donations welcome.

Saved you a mistake? Support VibeCalc

Why we built it

VibeCalc started as an Android app for the repeat math that shows up on job after job: slab volumes, stud counts, rafter lengths, baluster spacing, material counts, and early cost estimates. The website puts those same formulas in a browser tab.

No mystery math: concrete is L × W × T or π × r² × h. Studs come from wall length and on-center spacing. Rafters use the rise and run. Balusters are spaced from the available opening and the gap limit. Fence costs come from sections, posts, gates, waste, and labor. The formula is shown, and the answer updates as you type.

Check the math yourself

Chatbots can be handy, but they are not the tool I want for bag counts or stud layout. ORCA testing found leading AI chatbots got everyday math right about 45% to 63% of the time. VibeCalc uses fixed formulas printed on the page, so the same inputs give the same answer.

AI vs. construction math

Common questions

Is VibeCalc free to use?
Yes. The web calculators are free and do not ask for an email. They cover concrete, framing, rafters, roof pitch, balusters, decks, stairs, drywall, paint, tile, shingles, fence cost, excavation cost, and labor cost.
What construction calculators are included?
VibeCalc includes calculators for concrete volume, bag counts, wall studs, rafter length, roof pitch, baluster spacing, deck boards, stair stringers, drywall sheets, insulation, paint, tile, shingles, fence cost, excavation, and labor cost.
Does VibeCalc work with metric and imperial units?
Yes. You can use metric or imperial. VibeCalc starts with the unit system your browser region suggests, and you can switch it.
Why get the Android app if the web calculators are free?
The website is for quick browser checks. The free Android app is better when service is spotty or when you want voice input, material lists, and PDF export/share. Both are free, with no ads and no accounts.
Can I just ask an AI chatbot to do the construction math?
You can, but chatbots can slip on arithmetic. The ORCA benchmark found leading AI chatbots got everyday math right about 45% to 63% of the time. VibeCalc uses fixed formulas written and checked by people, so the same inputs give the same answer. Each calculator shows the formula it uses.

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.