What's new
Everything on this page is dated from the content itself. Where Calcrivo has no genuine date for something, this page reports a count instead of inventing one — see the note at the bottom.
Guides
- New guideHow to Calculate Age Exactly in Years, Months and Days
The borrowing method for exact age, how leap years and 29 February birthdays behave, and the month-end cases where two answers are both defensible.
- New guideHow to Calculate GST: Adding It, Removing It, and Splitting It
Add GST to a base price, strip it out of an inclusive one, split a rate into CGST and SGST, and see why input tax credit changes the maths.
- New guideHow EMI Is Calculated (And What Prepayment Actually Saves)
The EMI formula worked through on a 25 lakh loan, why early instalments are mostly interest, and what tenure and prepayment really change.
- New guideLinux Is Out of Disk Space: A Systematic Way to Find Out Why
Why df and du disagree, how deleted-but-open files consume space invisibly, and the order to check things in.
- New guideHow to Size Cloud Instances Without Overpaying
A practical method for right-sizing compute: measure before you buy, understand the pricing models, and know which metrics actually matter.
- New guideHow to Read Percentage Change Without Getting Fooled
Percent versus percentage point, why a 50% fall needs a 100% rise to recover, and how to reverse a percentage correctly.
- New guideCompound Interest Explained: Why Starting Early Beats Saving More
How compounding actually works, why frequency matters less than you think, and the arithmetic behind starting ten years earlier.
- New guideBMI Limitations: What It Misses and What to Measure Instead
Why BMI misclassifies athletes and older adults, how ethnicity shifts the thresholds, and which body measurements predict health risk better.
- New guideWhat Is CIDR Notation, and Why Did It Replace Network Classes?
CIDR explained from first principles: what the slash number means, why classes A/B/C were abandoned, and how to read any prefix at a glance.
- New guideUnderstanding Mortgage Amortisation: Where Your Payment Actually Goes
Why early mortgage payments are almost all interest, how overpaying works, and how to read an amortisation schedule properly.
- New guideHow to Calculate a Subnet Mask (By Hand and Quickly)
Work out subnet masks, network and broadcast addresses and host counts by hand — with the binary shortcuts network engineers actually use.
The calculator library today
- Calculators
- 19,813
- Categories
- 11
- Countries covered
- 200
What we currently publish
Not every calculator in the library is put forward as a search result. A page is only submitted for indexing once it carries a stated method, a worked example, specific questions and answers, stated assumptions, and text that is genuinely different from its sibling pages.
Right now 183 of 19,813 calculators meet that bar. The rest still work, are still linked, and are still searchable on the site — they are simply not offered to search engines while they are thin. Raising that number is the active work on this site, and how it is measured is described on the Methodology page.
Why this page is not a changelog
Individual calculators carry no publication or revision date in our data, so there is no honest way to tell you when a particular one was added or last changed. Rather than generate dates from build times — which would make every page look freshly updated after any deploy, including one that changed nothing — this page shows only what it can evidence. The quality figures above are recomputed from 19,813 measured calculator pages each time the site is built.