Chalk: Construction Calculator
Metric, Feet & Inches, Stairs
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
New: AI Advisor! ask how much to order and get answers in your units. Measure once, order right.
Chalk is the construction calculator that speaks your units. Metric first, flawless in feet and inches, and every result shown in both so nothing on site gets lost in translation.
Type measurements the way you say them. The purpose-built keypad takes 5 ft 3 1/2 in one line, with one-tap fraction keys or 2.45 m, or even a mix of both. No more converting in your head, no more decimal-feet guesswork.
THE TOOLBOX
• Stairs — risers, going, stringer length, angle and code check
• Rafters & Roof — common and hip/valley lengths from span and pitch
• Concrete — slabs, footings and post holes, with bag counts
• Framing & Studs — stud counts and plate lineal for any wall
• Drywall — sheets, screws, compound and tape
• Tiling — tiles, adhesive and grout, waste included
• Brick & Block — UK, AU and US sizes, plus mortar
• Decking — board rows, lineal length and fixings
• Board Feet — lumber volume and cost
• Equal Spacing & Balusters — even layouts that meet code
• Aggregates — gravel, sand, soil and asphalt by volume and tonnes
• Running Measurements — layout tables from a start and interval
• Chalk Pad — a full-size dimensional calculator with memory and rafter keys
• Plus a tape calculator, triangle solver, area & volume, pitch & slope, square check and a full unit converter
ASK THE ADVISOR
Chalk's AI Advisor talks the job through — quantities, materials, layout and sequencing. Attach a saved project and it works with your exact numbers. (The Advisor needs a connection; every calculator stays 100% offline.)
BUILT FOR THE SITE
• Works fully offline — no signal, no account, no ads
• Clear diagram on every calculator
• Saved projects keep every number with the job it belongs to
• Adjustable fraction precision down to 1/64″
• Rounded, glanceable results you can read in the sun
MADE FOR
Carpenters, builders, concreters, bricklayers, renovators and serious DIYers — anywhere metric and imperial meet.
Chalk Pro unlocks all trade calculators and saved projects. Subscriptions renew automatically until cancelled. Estimates only — always verify quantities before ordering.
Privacy: https://chalkcalc.com/privacy
Terms: https://chalkcalc.com/terms
Support: support@chalkcalc.com
Ratings & Reviews
The developer, Lionary LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Purchases
- User Content
- Identifiers
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Lionary LLC
- Size
- 19.8 MB
- Category
- Utilities
- Compatibility
Requires iOS 26.0 or later.
- iPhone
Requires iOS 26.0 or later. - Mac
Requires macOS 26.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Chalk Pro Weekly $2.99
- Chalk Pro Yearly $17.99
- Copyright
- © 2026 Chalk