Guides that explain what the tool is doing
Each guide starts with a tool you already use, then shows what happens under the hood with real numbers.
Page 1 of 5The “average” salary says ₹70,000, but most people there earn ₹32,000. Mean, median and mode explained.
One big number can drag the mean far from what a typical person gets. A seven-person example, when to use mean, median or mode, and the average-speed trap that gives 48 and not 50.
Read the guide, 3 minYour photo may be carrying your home address. Here is how to check.
Every phone photo can hide the camera model, the exact time and, if location is on, GPS coordinates accurate to a few metres. What EXIF is, how to read it, when it travels with the picture, and how to remove it before you share.
Pomodoro Timer (Focus & Break)The Pomodoro method, with the numbers: what 25 minutes on, 5 off really adds up to.
Eight rounds is a full working session, but it is four hours on the clock, not three and a half. How the cycle adds up, why 50/10 and 15/3 have the same ratio, and how to set a timer you will actually stick with.
Weighted Average CalculatorWeighted average calculator: how to find an average when some values count more than others
A plain average treats every number the same. A weighted average lets bigger or more important values count for more. This guide shows the formula, a worked example with course marks, how it differs from the simple average, and uses in grades, prices and portfolios.
Pro-Rata CalculatorPro-rata calculator: how to work out rent, salary or fees for part of a month or year
When someone joins, leaves or moves out in the middle of a period, the full amount has to be split fairly. This guide shows how pro-rata works, how the choice of days in the month changes the result, and where it is used for rent, pay and subscriptions.
Sales Commission CalculatorCommission calculator: how to work out sales commission, a bonus rate above target and total pay
Commission looks simple until a bonus rate starts above a sales target. This guide shows flat and tiered commission, which sales the higher rate applies to, the effective rate you really earn, and how a base salary changes total pay.
Final Grade CalculatorFinal grade calculator: how to find the score you need on the final exam to reach your target grade
Before an exam, the useful question is not what your grade is but what you need to score to reach the grade you want. This guide shows the formula, how the exam's weight changes the answer, and what to do when the number needed is above 100%.
Speed, Distance & Time CalculatorSpeed, distance and time calculator: how to find speed, distance or travel time, and why average speed is not a simple average
Speed, distance and time are linked by one formula, and knowing any two gives the third. This guide shows how to solve each case, how to convert km/h to metres per second, and why a trip at two speeds does not average to the middle value.
Profit Margin CalculatorProfit margin calculator: how to work out margin, profit and markup, and set a price for a target margin
Margin and markup sound alike but give different percentages for the same sale. This guide shows how to calculate profit, margin and markup from cost and selling price, and how to find the price that gives the margin you want.
Working Days CalculatorWorking days calculator: how to count business days between two dates and why holidays change the answer
Calendar days and working days are not the same. This guide shows how to count business days between two dates, what changes when the end date is included or the week has a different day off, and how to subtract public holidays by hand.
Days Until CalculatorDays until a date: how to count days, weeks and months to an event, and plan backwards from it
A deadline feels different when it is 84 days away than when it is 'three months' away. This guide shows how a countdown is worked out, whether today is counted, how to turn days into weeks and months, and how to plan a schedule backwards from a date.
Unit Price Comparison CalculatorUnit price calculator: how to compare pack sizes and find the real best buy per gram or per litre
Two packs, two prices and two sizes make it hard to see the cheaper one. Dividing price by quantity gives a unit price you can compare directly. This guide covers the method, the unit mix-ups to avoid, why the bigger pack is not always cheaper and how waste changes the answer.
GPA CalculatorGPA calculator: how to work out your grade point average, weighted by credits, and plan the next term
A GPA is not the plain average of your grades. Each course counts in proportion to its credits. This guide shows the 4.0 scale, a worked example, the mistake of ignoring credits, how to combine a new term with your existing GPA and the grade you need to reach a target.
Down Payment Calculator (Home & Car)Down payment calculator: how much to put down on a home and what it does to your EMI and total interest
The down payment decides how much you borrow, which sets the EMI and the interest you pay over 20 years. This guide shows the numbers for 10% to 40% down, the rules lenders follow, and the other costs on top, so you can choose an amount you can live with.
Overtime Pay CalculatorOvertime pay calculator: how to work out your hourly rate, the multiplier and what extra hours are worth
Overtime is paid at a higher rate than normal hours, but the final amount depends on how your hourly rate is worked out. This guide shows the formula, how the choice of monthly hours changes the result, and what common multipliers mean.
EV vs Petrol Car Running Cost CalculatorEV vs petrol savings calculator: running cost per km and how long the extra price takes to pay back
An electric car costs more to buy and far less to run. This guide works out petrol and electric cost per km, monthly and yearly savings and the payback time on the extra price, and shows how distance driven and home or public charging change the answer.
Freelance Hourly Rate CalculatorFreelance rate calculator: how to set an hourly rate that covers tax, expenses and time off
Dividing your wished-for salary by 2,080 working hours gives a rate that is far too low for a freelancer. This guide builds the rate from take-home goal, expenses, tax, billable hours and weeks off, with tables showing how each choice changes the number.
Rental Yield CalculatorRental yield calculator: gross vs net yield, payback years and whether a rental flat is worth it
Rent looks like free money until you subtract tax, repairs and empty months. This guide shows how to work out gross and net rental yield, what payback years really mean, how yield compares with a loan rate, and why rent is only half of a property's return.
Age CalculatorHow to calculate your exact age in years, months and days, and why leap years and cut-off dates matter
Age sounds simple until a form asks for it as on a particular date. This guide shows how exact age is worked out, how the days are borrowed from the previous month, how 29 February birthdays behave, and how to check eligibility on a cut-off date.
Subscription Cost CalculatorSubscription cost calculator: how small monthly payments add up, and how to audit them
A few streaming, app and gym plans can quietly cost more than a weekend trip every year. This guide shows how to add them up per month, per year and over five years, how to compare monthly and annual plans, and a simple audit to decide what to keep.
Net Worth CalculatorHow to calculate your net worth: assets minus debts, and what the number really tells you
Net worth is the single number that shows where you stand financially. This guide explains what to count, how to value each item honestly, how to read the debt-to-asset ratio and why a property-heavy net worth can still leave you short of cash.
Salary Hike CalculatorSalary hike calculator: how to work out your new salary and what a raise is really worth
Turn a hike percentage into a new yearly and monthly salary, see how hikes compound over a career, check what your raise is worth after inflation and find the percentage you need to ask for to reach a target.
VAT CalculatorHow to add and remove VAT from a price, and why subtracting the percentage is wrong
Adding VAT is a simple multiplication, but taking it back out trips up almost everyone. This guide shows both directions with worked examples, a rate table, the shortcut for finding the VAT inside a price, and how VAT is collected at every stage of a supply chain.
Tip & Bill Split CalculatorHow to calculate a tip and split a bill fairly, with 10%, 15% and 20% shortcuts
Work out the tip in your head in two seconds, see what each person owes when the bill does not divide evenly, and learn when to check for a service charge first. Includes lookup tables, a worked example and a fair way to settle up at the table.
UTM Link BuilderUTM parameters explained: source, medium, campaign and naming rules that keep reports clean
UTM tags are short labels added to a link so your analytics can tell which post, email or ad sent each visitor. They work only if you name things the same way every time. This guide covers the five parameters, a naming system, the mistakes that split your data, and when not to use them.
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