Free to use, provided as is, without warranty. The estimates (one-rep max, RPE conversions, attempt selection) are mathematical models, not coaching, medical or federation advice. Attempt conventions (90 % / 97,5 % / 102,5 % of a gym best) are common practice, not a rule: follow your federation.
Nothing is sold on this site at this stage. No account exists, no data is collected beyond the anonymous statistics described in the privacy page.
The pricing page describes what is planned (a one-payment version and an optional cloud add-on). It is a description of intent, not an offer to sell. If a paid version launches, terms will state price, renewal, refunds (planned: 30 days) and export of your data.
Strength Tools — free calculators. Not for sale at this stage.