EngiRef

• 12 printable reference sheets covering 311 rows - metric and UNC bolts, pipe schedules by schedule, AWG wire gauges, material properties by class, physical constants, and a formula sheet per discipline. Laid out for paper: black on white, column headers repeating at the top of every page, banded rows, and no row split across a page break. Print them or save them as PDFs.
• Take a material comparison away with you: export up to 6 materials as CSV, or print the comparison as its own sheet. Comparing them on screen is free.
• Create, save and calculate your own custom formulas with a real expression parser - operators, functions and constants, evaluated in your browser.
• Quiz the subject you are actually revising: pick any of the 6 disciplines and every round is reshuffled out of all 119 formulas. The free round is today's fixed set, identical for every visitor, and it is replayable.

Formula browsing, the unit converter, every reference table, physical constants, material property sheets, the full side-by-side comparison, today's replayable quiz round and your calculation history stay free forever, offline and without an account. History lives in your browser, which keeps your most recent 500 calculations and exports them as JSON whenever you want. Every figure on a reference sheet is free to read on the page it came from.

Premium is recognised per browser, so use Restore access with your access code to move it to another device. Checkout, cancellation and billing are handled by RevenueCat and Stripe; no card details ever reach this app or this page.

These are every storage key EngiRef writes, and it touches nothing else in this browser. No advertising or cross-site trackers are loaded; traffic measurement is Cloudflare Web Analytics, which is cookieless and aggregate-only.