CalculateItNow vs GigaCalculator
Built for people who cite things: BibTeX and IEEE citations, reference lists, and a claim of being featured in scientific journals.
Everything said here about GigaCalculator was read off their live site on , and the pages we opened are listed at the bottom. They may have changed since — if something below is out of date, believe them and not us.
GigaCalculator offers “hundreds of free online calculators and converters” and says “1.5 million people trust GIGAcalculator each month”. Its home page states that “Our calculators have been featured in multiple scientific papers and articles published in high-profile science journals”, and lists Springer, Wiley, Nature, Elsevier and Cambridge alongside media outlets including Business Insider and HuffPost.
The academic framing runs through the pages. Its loan calculator carries a “Cite this calculator & page” box offering Text (APA), Text (Chicago), Text (IEEE), HTML and BibTeX, generating a citation naming Georgi Georgiev with today's retrieval date. Its BMI calculator is authored by Georgiev, dated 30 May 2026, cites eight references, and includes a toggle for Asian and South-Asian BMI thresholds — the kind of population-specific detail most BMI pages leave out.
It sells display advertising, managed through Publift.
What GigaCalculator does better than us
Built to be cited
Five citation formats including BibTeX and IEEE, generated on the page with the retrieval date filled in. If you are writing a paper, a thesis or a lab report, that is a feature we do not have in any form.
A bibliography behind the number
Their BMI calculator lists eight references. Ours carry two or three, and never more than five. For a reader who wants to read the underlying literature rather than take the formula on trust, theirs goes further.
Standing in the literature, by their own account
They say their calculators have been featured in scientific papers published by Springer, Wiley, Nature, Elsevier and Cambridge. We have not independently counted those citations — but we have been cited by nobody at all, so the direction of the comparison is not in doubt.
Population-specific thresholds
The Asian / South-Asian BMI toggle reflects that the WHO cut-offs are not universal. It is a distinction a single WHO table leaves out, and it matters to a large part of the world's population.
Side by side
| GigaCalculator | CalculateItNow | |
|---|---|---|
| Citation export | APA, Chicago, IEEE, HTML and BibTeX, with a retrieval date | None |
| References on the page | Yes — e.g. eight on the BMI calculator | Sources on 329 of 331 — usually two or three, never more than five |
| Named author | Yes — Georgi Georgiev | None |
| Population-specific health thresholds | Yes — an Asian / South-Asian BMI toggle | Varies by calculator; no general toggle |
| Page dates | Per page — the BMI calculator reads 30 May 2026; the loan calculator reads 9 June 2023 | Per calculator, all of them September 2026 — because the site is new, not because it is maintained |
| Display advertising | Yes — ads.txt names Publift as manager | None |
| API for developers or AI assistants | Not offered on any page we checked | Free JSON API and a hosted MCP server, no key |
What we do that they don’t
Every calculation is a link
Your inputs live in the URL here, so a scenario can be sent to a colleague or reopened later exactly as it was.
Goal seek and sensitivity
Solve backwards for any input on 265 of our 331 calculators, and see which input actually moves the answer on 258.
No advertising
Their advertising runs through Publift — a normal way to fund a free reference site. We carry none, and no consent banner.
Callable by software and by AI assistants
A free JSON API with no key, and an MCP server so an assistant runs our tested code rather than doing arithmetic itself.
Math that gates the deploy
More than 3,800 automated tests run before anything ships, including reference values derived independently of the code. A wrong calculator stops the release.
Where we are weak
Against GigaCalculator specifically, these are the things you would be giving up by using this site:
- No citation export — no APA, no IEEE, no BibTeX, nothing. If you cite tools in your work, this is a real gap.
- Nobody has ever cited us, in a journal or anywhere else.
- Fewer references per page: two or three sources where theirs may list eight.
- No named author on any page.
- Our “Updated: September 2026” dates look excellent and mean very little — every page here was written this month.
Use GigaCalculator instead if…
- You need a citation in APA, Chicago, IEEE or BibTeX for a paper or a report.
- You want a reference list to read behind the formula.
- You want a tool whose use in published work you can point to.
- You need one of the converters or randomizers they have and we do not.
Go to GigaCalculator. We would rather you got the right answer somewhere else than the wrong one here.
How we checked
On we opened these pages and took the claims above from what they said that day. Nothing here comes from memory or from a third-party estimate; where we could not verify something, we left it out rather than guessing.
- Home page (scale, monthly users, journals claim)
- Loan calculator (citation formats, embed, last updated)
- BMI calculator (author, references, Asian BMI toggle, date)
- ads.txt (how the site is funded)
Our own figures are counted from the code that builds this site, at the moment you loaded this page: 331 calculators, 265 of them with goal seek and 258 with a sensitivity table. The test count is the exception — nothing here can count it — so it was taken by running the suite on 11 September 2026 and is written as a floor, because it goes up most weeks.