Span64 Construction Calculator

Exact trade math. Offline. Yours once.

Span64 is an exact feet-inch-fraction Calculator for carpenters, framers, contractors, and serious DIYers. Enter full equations, read stacked fractions clearly, convert between imperial and metric, and keep completed work on a persistent Tape.

THE CALCULATOR IS FREE

The Calculator is free. Jobsite Tools require a one-time unlock.

Add, subtract, multiply, and divide dimensions without ads. Calculator equations and results stay available on your Tape so you can reuse or share them later.

SPAN64 PRO: SEVEN JOBSITE TOOLS

• Triangle / Right-angle
• Area & Volume
• Concrete
• Board Feet
• Stairs
• Roof / Rafter, including common-rafter birdsmouth
• Studs / On-center

Preview every locked Tool with your own measurements before purchasing. A single non-consumable purchase reveals useful numeric results and unlocks all seven Tools forever. There is no subscription, trial countdown, or account.

BUILT FOR REAL WORK

• Exact domain math to 1/64 inch
• Tolerant feet-inch input
• Imperial and metric output where applicable
• Persistent Tape with notes and reuse
• Clear stair checks and focused jobsite forms
• Works without a signal after installation

Purchasing or restoring Span64 Pro requires a network connection so the App Store can verify ownership. Restore Purchases is available from Settings and the Span64 Pro screen.

Your measurements, equations, results, Tape entries, and notes stay on your device. Choose whether to share optional PostHog usage analytics and Sentry crash diagnostics after your first saved calculation. Both stay off unless you accept. You can change your choice in Settings. Telemetry uses a pseudonymous installation ID and never includes calculation content. Turning sharing off discards pending telemetry; see our Privacy Policy for data already sent and deletion requests.

Span64 is a calculation aid. Verify measurements, structural decisions, and local code requirements before cutting or building.