Calculators answer the number questions that come up all week: exact age for a form, GST on an invoice, the real monthly cost of a loan. Converters swap units and number systems. On ToolPeko the math runs in your browser, and the numbers you type are never stored.
Every tool below runs in your browser, on your own device. Open one, finish the job, close the tab. Nothing you use here is uploaded or stored.
Exact age in years, months and days for any form.
Marks, discounts and change, worked out properly.
Body mass index from height and weight, with its range.
Monthly loan payment, total interest and full cost.
The final price after a discount, and what you saved.
Add or remove GST at the rate your invoice uses.
Add tax to a price or pull it back out.
Work out a tip and split a bill between people.
See how savings grow when interest earns interest.
Mean, median, mode and range of any list of numbers.
Turn grades and credits into a GPA score.
Profit margin and markup from cost and selling price.
The chance of an event, as a fraction and a percent.
Hours and minutes between two times, added up cleanly.
Estimate ad earnings from views, CTR and CPC.
Cost per click from ad spend and clicks.
Cost per thousand views from spend and impressions.
See the fee on a payment before you send an invoice.
Length, weight, temperature and more in one box.
Meters, feet, inches, miles and kilometers swapped.
Kilograms, pounds, ounces and grams swapped.
Celsius, Fahrenheit and Kelvin, converted both ways.
A binary number turned into a plain decimal number.
A decimal number written out in binary.
Your words turned into binary code, and back again.
Binary code turned back into readable words.
A hex number turned into a decimal number.
A decimal number written out in hex.
Binary digits grouped and turned into hex.
An octal number turned into a decimal number.
A decimal number written out in octal.
An octal number turned into binary digits.
Binary digits turned into an octal number.
ASCII codes turned back into plain text.
Every letter of your text as its ASCII code.
Numbers to Roman numerals and back again.
A date written in Roman numerals, for tattoos and invites.
Forms, invoices and loan offers all ask for numbers nobody keeps in their head. How old exactly, in years and months? What does this loan really cost each month? Is GST already inside this price or on top of it? This page holds a calculator for each of those moments, plus the converters programmers and students live on.
Everyday money: Percentage Calculator handles marks, discounts and change. Discount Calculator gives the final price and what you saved. GST Calculator adds or removes GST at the rate your invoice uses, Sales Tax Calculator does the same job for sales tax, and Tip Calculator splits a bill fairly. Bigger decisions: EMI and Loan Calculator shows the monthly payment, the total interest and the full cost of a loan before you sign anything, and Compound Interest Calculator shows how savings grow when interest starts earning interest.
People and school: Age Calculator gives exact age in years, months and days, the way forms ask for it. BMI Calculator turns height and weight into a body mass index with its range. GPA Calculator turns grades and credit hours into a GPA. Plain math helpers sit alongside: Average Calculator for mean, median and mode, Probability Calculator, Hours Calculator for time between two times, and Margin Calculator for sellers setting prices.
Bloggers and advertisers get their own corner: AdSense Calculator estimates earnings from views, click rate and cost per click, with CPC Calculator and CPM Calculator for ad buying, and PayPal Fee Calculator shows the fee on a payment before an invoice goes out.
Converters: Unit Converter swaps length, weight and temperature in one box, with single-purpose versions at Length Converter, Weight Converter and Temperature Converter. Number systems live here too: Binary to Decimal, Decimal to Binary, Binary Translator, Binary to Text, Hex to Decimal, Decimal to Hex, Binary to Hex, the octal family, ASCII to Text, Text to ASCII, and for dates and tattoos alike, Roman Numeral Converter and Roman Numerals Date Converter.
| Your problem | Use this | Why it fits |
|---|---|---|
| The form asks my age on a specific date | Age Calculator | Years, months and days, counted exactly |
| A loan looks cheap but I smell a catch | EMI and Loan Calculator | Monthly payment and the total interest, in the open |
| Is GST inside this price or added on top? | GST Calculator | Both directions, at the rate you pick |
| I scored 45 out of 60 and need the percent | Percentage Calculator | Marks, discounts and change in one place |
| Six friends, one bill, no arguments | Tip Calculator | Tip and split worked out per person |
| My doctor mentioned BMI and I want mine | BMI Calculator | Your number with the standard range beside it |
| My homework is in binary and my brain is not | Binary to Decimal | Converts both ways, with the family beside it |
| A client pays through PayPal and I eat the fee | PayPal Fee Calculator | See the fee, then price the invoice right |
Every calculator on this page is a standard formula running in your browser. The numbers you type never leave your device, which is a real comfort when the numbers are your salary, your weight or your loan. There is nothing to sign up for and nothing is saved when you close the tab.
Where a calculator’s answer ends and real life begins:
A mother works out her son’s exact age for a school form that counts months, not birthdays. A freelancer adds the PayPal fee into an invoice instead of quietly losing it. A shopper checks what a 12 percent loan on a phone really costs over two years, and walks away from it. A student converts binary homework both ways until the pattern clicks. Small numbers, decided properly, on the spot.
Yes. Every calculator and converter on this page is free, with no sign-up and no limit on how often you use them. ToolPeko earns from ads on the site.
No. The math runs in your browser. Your salary, weight, dates and loan figures never travel to a server, and closing the tab clears them.
It counts exact calendar years, months and days between the two dates, including leap years. That is the count forms and offices use when they ask for age on a given date.
Use it to judge and compare offers: the monthly payment and total interest are worked out with the standard formula. Your bank’s final schedule governs the loan itself, since fees differ by lender.
The rate your country charges on that product or service. Rates differ by country and category, and they change over time, so the calculator takes the rate from you rather than guessing.
Binary, hex and octal are how computers store and address numbers, so they fill computer science homework. The converters here show both directions, which is how the pattern is actually learned.
Yes. They run in the browser on Android and iPhone, and on Windows and Mac. A form question that appears while you are out can be answered where you stand.
This is only one drawer of the toolbox. The rest work the same way: free, in your browser, with nothing uploaded.