01
Refract
A loan is not one number. It is a principal, a rate, a term, an amortization curve and a total cost. A body is not one number either. We start by breaking the input into the parts that actually decide the outcome.
NumberPrism
The idea
A prism for the numbers that shape a life.
NumberPrism exists because most calculator sites stop at the answer. We wanted the other half: the parts, the range, the schedule, the assumptions — the full spectrum behind a number.
Why the name
The light was always there.
A prism does not invent colour. It takes one beam of white light and separates it into the spectrum that was already inside. The beam is unchanged; what changes is our ability to see it.
That is the job of a good calculator. The arithmetic is not magic, and the answer should not be mysterious. A loan payment, a BMI range or an equation has parts, assumptions and consequences. Separating them is what turns a number into a decision.
Number is the raw material: money, measurements, dates, equations, risk. Prism is the method: honest, multi-faceted, transparent.
One input
A loan, a body, an equation, a date.
One method
Separate it into the parts that matter.
One spectrum
Payments, ranges, schedules and what-ifs.
The method
Three moves, every time.
02
Reveal
The result is never a single opaque figure. It is a schedule, a chart, a healthy range, a set of assumptions — the full spectrum of what the numbers mean, including the parts that are inconvenient.
03
Resolve
You should leave with something you can act on, not a screen of noise. Every calculator resolves to a clear result, and every calculation runs in your browser rather than on our servers.
What is inside the prism
Ten families of tools — finance, health, math, date and time, converters, home, food, travel, business and everyday fun — plus embeddable widgets. Everything is free and usable without an account.
Finance & investment
Mortgages, loans, SIP, retirement, compound interest and the real cost of borrowing.
ExploreHealth & fitness
BMI, BMR, body fat, calories, pregnancy and ovulation — with ranges, not judgements.
ExploreMath & education
Scientific, fraction, percentage, GPA and final-grade tools that show the steps.
ExploreEveryday & fun
Bills, decisions, passwords and quick utilities that stay in your browser.
ExploreGlobal by default
Currency, units and rates stay editable, so a calculator is not tied to one tax code or country.
ExploreEmbeddable widgets
Put a NumberPrism calculator on your own site with one script tag.
ExplorePrivate by construction
There is no account, no upload and no calculation server. Inputs stay in your browser's memory. The only things saved locally are preferences you choose, such as theme and favourites, and you can clear them at any time.
Show the working
Each calculator implements a published formula and explains its assumptions. Where a rule changes — a tax slab, a rate, a health threshold — the page says which version it applies. When we are wrong, we correct the calculator, not just the paragraph around it.
Who keeps it honest
The NumberPrism Editorial Team is accountable for the formulas, the written explanations and every correction on this site. It is an independent editorial desk, not a bank, broker or medical practice — and it does not sell the data you type.
The full standards are in our editorial policy. Corrections are welcome at hello@numberprism.com.