Choose a plan
Unlock everything
- 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.
Weekly, yearly and lifetime plans are available. Live prices load below; the yearly plan works out cheapest per week, and lifetime is a single payment with no renewal and no expiry date.
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.
What stays free?
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. A sample of every printable sheet renders for everyone, in its real column layout, so you can judge one before buying. No account is needed for any of it.
If every number is free, what am I paying for?
The format. A printable sheet puts a whole table on paper the way you actually use it at a bench or on site - black on white, column headers repeating at the top of every page, banded rows, nothing split across a break. The same goes for the material comparison: comparing on screen is free, taking the comparison away as a CSV or a printed sheet is the paid part.
See the sheets
How is my access stored?
Purchases are handled by RevenueCat and Stripe. An anonymous purchase id is kept in this browser so EngiRef recognises your Premium access on this device. Keep your receipt email for recovery.
I already subscribed on another device - how do I get access here?
Open the Premium page on the device where you subscribed, copy the access code shown there (or use your receipt), then restore it on this browser.
Restore access
Can I cancel?
Yes. Subscriptions renew automatically and can be cancelled anytime from the link in your receipt email. Lifetime is a one-time payment, so there is nothing to cancel.
What does the Lifetime plan actually cover?
Lifetime is one payment with no renewal and no expiry date. It unlocks exactly what a weekly or yearly plan unlocks: the printable reference sheets, the comparison exports, your own custom formulas and discipline-picked quiz rounds. It is tied to this site rather than to a number of years, so it lasts for as long as EngiRef is online, and like every plan it is held in this browser and moves to another one with your access code. Premium is a single unlock rather than a purchase of individual sheets, so if a reference sheet is added to EngiRef later, your access opens it at no extra cost. That is how the unlock works, and it is not a promise that anything more is on the way.
I lost my access code - can you help?
Yes. Reach out through the support channel on our Privacy page from the email address on your receipt, and we can look up your access code.
Contact via Privacy page