How it works
1. Pick a calculator
Choose the trade you need: construction math, electrical, plumbing, coverage, concrete or HVAC. Every tool is built for the field.
2. Enter your numbers
Type dimensions, loads or readings. Results update as you go, with the units and fractions you actually work in.
3. See materials and cost
Every calculator gives you the quantity you need and the cost to buy it, so you can order and quote with confidence.
All the calculators, by trade
Construction math
- Feet, inches and fractions calculator
- Add, subtract, multiply and divide in real measurements
- Square footage and area
Electrical
- Ohm's Law (volts, amps, ohms, watts)
- Voltage drop
- Wire size and ampacity
- Conduit fill
Plumbing
- Pipe size
- Flow rate (GPM)
Coverage
- Tile
- Flooring
- Paint
- Drywall
Concrete and asphalt
- Concrete slab
- Concrete footing
- Asphalt tonnage
HVAC
- AC tonnage
- CFM (airflow)
Every calculator estimates the materials you need and the cost to buy them, all on your device, all offline.
Simple pricing
Lifetime
Unlock every calculator forever with a single one-time purchase. No subscription, nothing renews. The same price as one year, paid once.
Weekly
Every calculator unlocked, billed weekly. Starts with a 3-day free trial; cancel during the trial and you are never charged.
Annual
Every calculator unlocked for a year, billed annually.
A few calculators are free forever: the feet, inches and fractions calculator, Ohm's Law and square footage. The rest unlock with any purchase. Prices in USD and may vary by region. Subscriptions are billed through your Apple ID and renew automatically unless cancelled at least 24 hours before the end of the current period. Terms.
Questions
Does it work offline?
Yes. The app is 100% offline. Every calculator works anywhere on the job site, with no internet connection at all.
Is it really pay-once?
Yes. The Lifetime unlock is a single $19.99 one-time purchase that unlocks every calculator forever, with no subscription and nothing to renew. Weekly and annual plans are also available if you prefer.
Do you collect my data?
No. The app collects no data at all. There are no accounts, no analytics, no ads and no tracking, and the app makes no network calls. Everything you enter and every calculation stays on your device.
What is free?
The feet, inches and fractions calculator, Ohm's Law and square footage are free forever. Any purchase unlocks the rest: electrical, plumbing, coverage, concrete, asphalt and HVAC calculators.
How do I cancel a subscription?
Subscriptions are managed by Apple. Cancel anytime in your Apple ID subscription settings. The Lifetime option is a one-time purchase with nothing to cancel.