What this is
SolveTutor is a reference collection of calculators — finance, health, mathematics, physics, conversion and the workshop — built to a single standard: each one states the formula it uses, shows the working for your numbers, cites its sources, and refuses to display a figure it cannot justify.
The name is deliberate. These are meant to feel like instruments rather than widgets: numbered, calibrated, documented, and honest about their tolerances. 3718 are in service today; 3,900 are catalogued and being built in batches.
Who makes it
SolveTutor is an independent project — a small editorial and engineering effort, not a large company and not a team of credentialed specialists. We think you should know that plainly, because it tells you how to read the pages: we are careful about arithmetic, we cite the sources our formulas come from, and we do not pretend to clinical, legal or financial authority we do not have.
What we can promise is process, and it is documented in full on the methodology page: every formula implemented twice in two independent languages, checked against cited test cases, with a build that fails rather than publish a disagreement.
How it is paid for
Right now, nothing on this site is monetised: there are no advertisements, no affiliate links, no sponsored calculators and no paid placements. If advertising is introduced later to cover hosting and development, it will be clearly marked as advertising, it will never influence which instruments we build or what a result says, and the privacy page will be updated before it appears rather than after.
What we will not do
- Publish a figure we have not verified against an independent implementation.
- Invent authorship, credentials, testimonials or statistics to look more authoritative.
- Fill an undefined result with a plausible number so the page looks complete.
- Copy explanations from other calculator sites.
Corrections
If a result here disagrees with a source you trust, we want to know — that is the fastest way this collection gets better. Send the instrument, the inputs and the figure you expected via the contact page.