The Rule of 72
Divide 72 by an annual return to estimate how many years it takes money to double. At 8%, about 9 years; at 12%, about 6. It works in reverse for inflation: at 6% inflation, prices double in about 12 years.
Free · No sign-up · Built for the whole world
Numbers, settled — instantly.
Eight precision calculators on one page — loans, savings, tax, currency, health and time — each with the formula shown and the working explained, so you understand the number and not just see it.
- 8 everyday calculators
- 15 currencies, live rates
- 0 data stored
Jump to: Which calculator?How EMI worksMoney rulesGlossaryAll calculators →
01
EMI Calculator
Work out the monthly installment on a home, car, personal or education loan — complete with a principal-vs-interest breakdown, a full year-by-year amortization schedule, and a prepayment planner that shows exactly how much interest an extra monthly payment saves you.
Monthly EMI—
Total Interest—
Processing Fee—
Total Payment—
Payoff Time With Prepayment—
Interest Saved—
Principal —
Interest —
| Year | Principal Paid | Interest Paid | Balance |
|---|
EMI = P × r × (1+r)n / ((1+r)n − 1) — where P is principal, r is the monthly interest rate, and n is the number of monthly installments.
02
Currency Converter
Convert between 15 major world currencies using near real-time mid-market exchange rates, with one-tap shortcuts for the most searched currency pairs and a live rate table for every popular currency at once.
Converted Amount—
Exchange Rate—
Fetching live rates…
1 USD is worth
Rates shown are indicative mid-market rates, not transaction rates. Banks, card networks and exchange counters typically add a margin of roughly 1–3% plus a fixed fee, so the amount you actually pay or receive may differ slightly.
03
BMI Calculator
Calculate Body Mass Index from height and weight in metric or imperial units, see exactly where you land on the WHO weight-category scale, and get the healthy weight range for your own height.
Your BMI—
Category—
Healthy Weight Range—
1618.5253040+
Enter your height and weight to see where you fall on the scale.
04
Age Calculator
Find your exact age in years, months and days, plus total weeks, hours and days lived, the day of the week you were born, and a live countdown to your next birthday.
Your Age—
Total Days Lived—
—Weeks lived
—Months lived
—Hours lived
—Born on a
—Days to next birthday
—Zodiac sign
05
Percentage Calculator
Four calculators in one: find a percentage of a number, work out what percentage one number is of another, calculate the percentage increase or decrease between two numbers, or find the result of applying a percentage change.
Result—
Choose a mode above — the formula and labels update automatically to match.
06
GST & Discount Calculator
Apply a discount and tax (GST/VAT) to a price, or work backwards from a tax-inclusive total to find the original base price and the exact tax amount — with an optional CGST + SGST split for invoicing.
After Discount—
Tax Amount—
CGST + SGST—
Final Price—
Invoice breakdown
07
Compound Interest Calculator
Project how a lump sum — plus an optional recurring monthly contribution — grows over time at a chosen compounding frequency, with a year-by-year growth table and a side-by-side comparison against simple interest.
Total Invested—
Total Interest Earned—
Maturity Value—
vs. Simple Interest—
| Year | Invested | Interest | Balance |
|---|
08
Unit Converter
Convert length, weight, area, volume, speed, digital storage, time and temperature instantly between metric, imperial and other common units.
Converted Value—
Start here
Which calculator answers your question?
Every tool on 7EMI is built around one everyday question. Find yours, see the maths behind it, and open the dedicated page for worked examples and a deeper guide.
Loans
"How much will I pay every month?"
EMI = P·r·(1+r)ⁿ ÷ ((1+r)ⁿ − 1)
Monthly installment, total interest, a year-by-year schedule and how much a prepayment saves.
EMI Calculator → Savings"What will my money grow to?"
A = P(1 + r/n)ⁿᵗ
Lump sum plus monthly top-ups, with the gap between compound and simple interest made visible.
Compound Interest → Tax"How much of this price is tax?"
Base = Total ÷ (1 + rate)
Add GST or VAT, strip it out of an inclusive price, apply a discount first, and split CGST + SGST.
GST & Discount → Travel & trade"What is this worth in my currency?"
Amount × (rateto ÷ ratefrom)
Near real-time mid-market rates for 15 widely used currencies, with an offline fallback.
Currency Converter → Health"Is my weight in a healthy range?"
BMI = kg ÷ m²
Your BMI, its WHO category, and the weight range that keeps you between 18.5 and 24.9.
BMI Calculator → Everyday maths"What percent is that?"
% change = (new − old) ÷ old × 100
Percent of a number, what share one number is of another, and growth or drop between two values.
Percentage Calculator → Dates"Exactly how old — or how long?"
years · months · days
Calendar-accurate age or the gap between two dates, with leap years handled for you.
Age Calculator → Measurement"What's that in metric?"
°F = °C × 9/5 + 32
Length, weight and temperature between metric and imperial units in one step.
Unit Converter →EMI, explained
Where your EMI actually goes — year by year
An EMI stays the same every month, but what it pays for does not. Interest is charged on the balance you still owe, so in the early years most of each payment is interest. As the balance shrinks, the interest portion falls and more of the same EMI starts reducing your loan.
Take a ₹20 lakh home loan at 8.75% for 20 years. The EMI is ₹17,674, which is ₹2.12 lakh a year. In year one, about 82% of that goes to interest. You only cross the halfway point of repaying the principal in month 167 — almost 14 years into a 20-year loan.
Why it matters: a prepayment made in the first few years cuts far more interest than the same amount paid near the end, because it removes balance that would otherwise have been charged interest for many more years.
| Year | Interest paid | Principal repaid | Interest share |
|---|---|---|---|
| 1 | ₹1,73,476 | ₹38,615 | 82% |
| 5 | ₹1,57,363 | ₹54,727 | 74% |
| 10 | ₹1,27,461 | ₹84,629 | 60% |
| 15 | ₹81,222 | ₹1,30,868 | 38% |
| 20 | ₹9,719 | ₹2,02,371 | 5% |
Reducing-balance method, monthly rests. See every year in the EMI calculator's schedule.
Tenure vs. cost
A smaller EMI can mean a much bigger bill
Stretching a loan lowers the monthly payment, but you pay interest for longer. Here is the same ₹25 lakh loan at 8.75% over five different tenures.
| Tenure | Monthly EMI | Total interest | Interest as % of loan |
|---|---|---|---|
| 10 years | ₹31,332 | ₹12.6 lakh | 50% |
| 15 years | ₹24,986 | ₹20.0 lakh | 80% |
| 20 years | ₹22,093 | ₹28.0 lakh | 112% |
| 25 years | ₹20,554 | ₹36.7 lakh | 147% |
| 30 years | ₹19,668 | ₹45.8 lakh | 183% |
Going from 20 to 30 years saves ₹2,425 a month — and costs about ₹17.8 lakh more in interest. A useful middle path: choose the longer tenure for safety, then prepay whenever you can. Try your own numbers →
Read the fine print
"10% flat" is not 10%
Some personal, two-wheeler and consumer-durable loans quote a flat rate: interest is worked out on the full original amount for the whole tenure, even though you repay part of it every month. Banks and most lenders quote a reducing-balance rate instead, where interest is only charged on what you still owe.
On a ₹5 lakh loan for 3 years at 10% flat, interest is ₹1.5 lakh and the EMI is ₹18,056. To produce that same EMI on a reducing balance, the rate would have to be about 17.9%. Always convert a flat quote before comparing offers.
Flat rate quote
10%
Interest on the full ₹5,00,000 for 3 years
=
Real reducing rate
≈ 17.9%
Same ₹18,056 EMI, interest on the falling balance
Use the reducing balance EMI calculator to check any quote.
Rules of thumb
Six money shortcuts worth remembering
Keep total EMIs in check
Lenders look at how much of your monthly income already goes to EMIs. Many people aim to keep all EMIs together at or below roughly 40% of take-home pay, so a job change or emergency doesn't break the budget.
Prepay early, not late
Because interest is front-loaded, extra payments in the first third of a loan do the most work. Ask your lender to apply a prepayment to principal and to reduce tenure, not just the EMI.
Compare total cost, not just rate
A lower rate with a high processing fee can cost more than a slightly higher rate with no fee. Add every upfront charge to the total interest before choosing between two offers.
Divide, don't subtract, for tax
To find the pre-tax price inside an 18% GST total, divide by 1.18. Taking 18% off the total overstates the tax — ₹1,180 contains ₹180 of tax, not ₹212.40.
The "rate" you see is the mid-rate
Converter rates are mid-market rates. Banks, cards and money changers add a margin on top, so the amount you actually receive will usually be a little lower than the conversion shows.
Rate watch · India · updated Oct 2026
Repo rate is now 5.50% — what changes for borrowers
The RBI raised the repo rate by 0.25% on 7 October 2026, its first increase since February 2023. Repo-linked home loans reset at least once a quarter, so most floating-rate borrowers will see a slightly higher EMI — about ₹795 a month on a ₹50 lakh, 20-year loan — or a longer tenure if the lender keeps the EMI unchanged.
Read the full breakdown →- Repo rate
- 5.50%
- Change
- +0.25%
- Policy date
- 7 Oct 2026
- Stance
- Tightening
Glossary
Loan & money terms in plain English
- Principal
- The amount you borrow, before any interest is added.
- Tenure
- How long you take to repay the loan, usually counted in months.
- Amortization
- Paying a loan off through a fixed schedule in which each EMI covers that month's interest plus a slice of principal.
- Reducing balance
- Interest is charged only on the amount still outstanding, so it falls as you repay.
- Flat rate
- Interest calculated on the original amount for the full tenure — costlier than the same headline reducing rate.
- Repo rate
- The rate at which the RBI lends short-term money to banks. Repo-linked loans move with it.
- EBLR / RLLR
- A loan rate set as an external benchmark (usually repo) plus a fixed spread. Most new floating home loans in India use it.
- MCLR
- A bank's internal lending benchmark, used for many loans taken before October 2019. It resets less often.
- Prepayment
- Paying extra principal before it is due, to cut interest or shorten the loan.
- Compounding
- Earning interest on interest already earned — the engine behind long-term savings growth.
- CGST + SGST
- The two equal halves GST is split into on an intra-state sale in India.
- Mid-market rate
- The midpoint between buy and sell prices for a currency, before any provider's margin.
How we calculate
Built to be checked, not just trusted
Standard formulas
EMI uses the reducing-balance annuity formula banks use; compound interest uses the standard periodic-compounding formula; BMI follows WHO categories. Each formula is printed on the calculator so you can verify it by hand.
Nothing leaves your device
All maths runs in your browser. Loan amounts, birth dates and body measurements are never sent to our servers or saved. The currency converter only fetches public exchange rates.
Estimates, clearly labelled
Lenders may round differently, charge fees or use daily interest. Treat results as a close guide for planning and confirm final numbers with your bank, tax advisor or doctor.
Frequently Asked Questions
Is 7EMI free to use?
Yes. Every calculator on 7EMI is completely free, with no sign-up, no account, and no usage limits.
How is EMI calculated?
EMI is calculated using the formula EMI = P × r × (1+r)n / ((1+r)n − 1), where P is the principal loan amount, r is the monthly interest rate, and n is the number of monthly installments.
Does the EMI calculator include processing fees?
No, the EMI figure covers only principal and interest on a reducing-balance basis. Processing fees, insurance, and other charges vary by lender and aren't included.
Are the currency exchange rates live?
Yes — the converter pulls near real-time rates for major world currencies including USD, EUR, GBP, INR, JPY, AUD, CAD, AED, SGD and CNY. If the live feed is briefly unavailable, an approximate offline rate is shown instead.
Which currencies does the converter support?
USD, EUR, GBP, INR, JPY, AUD, CAD, AED, SGD, CNY, CHF, ZAR, BRL, RUB and SAR — the currencies most commonly searched for worldwide.
What is a healthy BMI range?
For most adults, a BMI between 18.5 and 24.9 is considered a healthy weight range. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is obese. BMI is a general indicator, not a medical diagnosis.
Does the Age Calculator account for leap years?
Yes, it uses standard calendar math so leap years are automatically handled correctly when counting years, months, and days.
How does the Percentage Calculator work?
Toggle between "X% of Y" to find a percentage of a number, or "X is what % of Y" to find what percentage one number represents of another.
Does the GST/Discount calculator apply discount before or after tax?
Discount is applied to the original price first, and GST/VAT is then calculated on the discounted amount — matching how most retail and invoicing systems work.
What compounding frequency should I use for Compound Interest?
Use whatever frequency your bank or investment product actually compounds at — usually stated in the product's terms. Monthly compounding yields slightly more than yearly, for the same stated annual rate.
Does the Unit Converter support temperature?
Yes — switch the toggle at the top of the Unit Converter between Length, Weight, and Temperature (Celsius, Fahrenheit, and Kelvin).
Does 7EMI store the numbers I enter?
No. Every calculation runs locally in your browser. Your loan amounts, weight, birth date, and other inputs are never sent to or stored on our servers.
Can I use 7EMI on my phone?
Yes — the site is fully responsive and works smoothly on phones, tablets, and desktop browsers alike.
Can I link directly to one calculator?
Yes. Each calculator has its own URL section — for example 7emi.com/#currency opens directly to the Currency Converter.
Is there a dark mode?
Yes — use the circular toggle in the top-right corner of the header. Your preference is remembered for future visits.
I found a bug or incorrect result — what should I do?
Please contact us with the calculator name and the inputs you used, and we'll look into it as quickly as possible.
Does the EMI calculator show a full amortization schedule?
Yes. Open "View year-by-year schedule" under the EMI result to see the principal paid, interest paid and remaining balance for every year of the loan term.
How does the prepayment planner work?
Add an extra monthly payment on top of your EMI and the calculator instantly shows your new payoff time and the total interest that extra payment saves you over the life of the loan.
How is the healthy weight range worked out?
It's the weight span that keeps your BMI between 18.5 and 24.9 at the height you entered — shown right alongside your BMI result and category.
Can the GST calculator work backwards from a tax-inclusive price?
Yes — switch to "Price includes tax" and enter the final amount to see the original base price and the exact tax it contains, with an optional CGST + SGST split for invoicing.
Does the compound interest calculator support monthly contributions?
Yes — add a monthly contribution to model a recurring investment alongside your lump sum, and compare the outcome directly against simple interest.