About Calvix

Calvix started as a folder of spreadsheets. Every time a bank quoted an EMI, a CA mentioned a slab, or a college asked for a percentage that the marksheet only gave as a CGPA, we ended up rebuilding the same arithmetic to check the figure we had been handed. The calculators here are those spreadsheets, cleaned up and put online so we stop redoing them, and so you do not have to build your own.

The one rule is that a number on its own is not much use. If a calculator says your EMI is ₹21,696 but not where that comes from, you cannot check it against the sanction letter, cannot adapt it when the rate resets, and cannot tell whether the lender's version quietly used a flat rate. So every page shows the formula, works a real example in rupees, and says where the model stops applying.

Who writes this

Every page is written and maintained by the Calvix Team, a small group of people in India who build the calculators, write the explanations and keep the statutory figures current. We are not chartered accountants or doctors and do not pretend to be; where a page touches tax or health it names the rule or the formula it relies on so you can check it, and it says when it was last reviewed. If you spot a figure that has moved since, tell us.

Written for India, not translated for it

Most calculator sites are American tools with the dollar sign swapped out. The defaults are wrong, the tax is wrong, and the advice underneath is about a country with different banks and different rules. Here the loan pages talk about stamp duty and RBI loan-to-value caps, the tax pages follow the Indian financial year and the section numbers a CA would use, the student pages know that VTU and CBSE convert CGPA differently, and the bill split knows that GST is charged on the service charge. Where a rule differs by state, the page says so rather than picking one and hoping.

How the formulas are checked

Each formula is a standalone function with automated tests that run before anything is published. The tests spend most of their effort on the awkward cases (zero interest, a tenure of two and a half years, an empty field, a deposit larger than the price) because those are where calculators quietly produce nonsense. The worked example in each article is produced by the same code that runs the calculator, so the two cannot drift apart.

Statutory figures such as tax slabs, TDS rates and the gratuity ceiling are quoted with the financial year they apply to. They change every Budget. If a page shows a year that has passed, treat the figure as a starting point and check the current one.

What these calculators are not

They are estimates for general information. They are not financial, medical, tax or legal advice, and they cannot know your circumstances. Banks round differently, hospitals use different reference ranges, and your CA may know a deduction the page does not. Use a result to ask better questions, not to skip asking them.

Privacy

Calculations run entirely in your browser. Nothing you type is sent to a server or stored anywhere. See the privacy policy for what the analytics and advertising scripts do collect.

Corrections

If a result looks wrong, it might be. Write in with the calculator, the inputs and the figure you expected, ideally with where that figure came from. A reproducible example gets fixed fastest.