Finance
This hub covers pricing, lending and personal-finance math: loan and interest calculators (EMI, compound interest and simple interest), pricing tools (discount, VAT, markup and profit margin) and budgeting tools (debt-to-income, rent affordability and savings goals). Tools that share a formula, such as the VAT Calculator and Sales Tax Calculator, link to each other so you can compare approaches.
Loan EMI Calculator
Estimate monthly loan payment, total payment and interest.
SALEDiscount Calculator
Calculate sale price and money saved from a discount.
VATVAT Calculator
Add tax to a net amount or extract tax from a gross total.
TIPTip Calculator
Split a bill with a percentage tip across multiple people.
CICompound Interest Calculator
Project compound growth over time with selectable compounding frequency.
SISimple Interest Calculator
Calculate simple interest and final amount from principal, rate and time.
$/HSalary to Hourly Calculator
Convert annual salary into hourly, weekly and monthly equivalents.
MARGINProfit Margin Calculator
Calculate gross profit and profit margin percentage from revenue and cost.
MARKUPMarkup Calculator
Calculate markup percentage from cost and selling price.
BEPBreak-Even Calculator
Estimate the number of units needed to cover fixed and variable costs.
SAVESavings Goal Calculator
Estimate how many months regular deposits need to reach a savings target.
ROIInvestment Return Calculator
Calculate investment gain or loss and simple return on investment percentage.
COMMCommission Calculator
Calculate commission earnings from sales and a percentage rate.
TAXSales Tax Calculator
Add a percentage sales tax to a subtotal.
DTIDebt-to-Income Calculator
Estimate monthly debt-to-income ratio from debt payments and gross income.
RENTRent Affordability Calculator
Estimate a monthly rent budget from income and a chosen percentage.
FX FEECurrency Conversion Fee Calculator
Estimate percentage and flat fees charged on a currency conversion amount.
MTGMortgage Calculator
Estimate monthly mortgage payment from home price, down payment and interest rate.
CARCar Loan Calculator
Estimate monthly car loan payment from price, down payment, trade-in and rate.
ZAKATZakat Calculator
Estimate annual Zakat due on cash, gold, silver and other assets.
What you will find in the Finance category
This category brings together the calculators that people use to understand money decisions. For borrowing there are the Loan EMI Calculator, the Car Loan Calculator, the Mortgage Calculator and the Debt-to-Income Calculator. For interest and growth there are the Simple Interest Calculator, the Compound Interest Calculator, the Investment Return Calculator and the Savings Goal Calculator. For pricing and business there are the Discount Calculator, the Markup Calculator, the Profit Margin Calculator, the Break-Even Calculator and the Commission Calculator. For tax and daily money there are the VAT Calculator, the Sales Tax Calculator, the Tip Calculator, the Salary to Hourly Calculator, the Rent Affordability Calculator, the Currency Conversion Fee Calculator and the Zakat Calculator.
Borrowing: loans, cars and homes
Loan calculators answer the question that matters first: what will it cost each month and in total? The loan EMI calculator uses the reducing-balance method that most banks use, the car loan calculator subtracts the down payment and trade-in, and the mortgage calculator shows principal and interest for a long term. They also show how the term changes the cost: a longer loan has a smaller payment but more interest. The debt-to-income calculator tells you how much of your gross income is committed to debt, which is the ratio lenders look at. Test several terms and rates before you apply, and ask lenders for the annual percentage rate, since fees change the real cost of a loan.
Interest, growth and saving
Interest works in two ways. Simple interest is calculated only on the original amount, which is common for short loans and deposits, while compound interest is added to the balance and then earns interest itself, which is why long-term savings grow faster than they seem to at first. The compound interest calculator lets you change the rate, the period and the compounding frequency, and the investment return calculator turns a gain into a percentage return. The savings goal calculator works out how many months a regular deposit needs to reach a target. Together they show the effect of time, rate and consistency, and why starting early matters.
Pricing, margins and running a small business
Sellers need to price carefully. The markup calculator adds a percentage to cost, while the profit margin calculator shows profit as a percentage of the selling price, and the two are not the same: a 50 percent markup is a 33 percent margin. The discount calculator shows what a sale does to the price, and the break-even calculator tells you how many units you must sell to cover fixed costs. The commission calculator helps salespeople and managers check earnings. Use these tools together before launching a product or a promotion, and include costs such as packaging, payment fees and returns, which are easy to forget.
Tax, tips and day-to-day money
Everyday tools deal with the small amounts that add up. The VAT and sales tax calculators add tax to a price or take it out of a total, and the difference between the two is that VAT prices usually include the tax while sales tax is added at the till. The tip calculator splits a bill with a tip, the salary to hourly calculator converts pay between yearly, monthly and hourly figures, and the rent affordability calculator suggests a rent budget from income. The currency conversion fee calculator measures the fees on a transfer or a card payment abroad, although it cannot see the margin hidden in an exchange rate.
Zakat and values-based finance
The zakat calculator helps Muslims estimate the yearly obligation on wealth, commonly 2.5 percent of zakatable assets that exceed the nisab and have been held for a lunar year. It totals the cash, savings, gold, silver, trade goods and money owed to you that you enter, minus debts that are due. Scholars differ on details such as jewellery, retirement funds and business assets, and the calculator cannot decide a ruling, so you should ask a qualified scholar about anything that is not straightforward. Keep a record of your assets and your calculation on the same date each year so that the figure is consistent and easy to review.
Common mistakes in money calculations
Several errors are common. People confuse markup with margin, compare loans by monthly payment instead of total cost, compare a nominal rate with an effective rate, forget fees, and apply a discount and a tax in the wrong order. They treat simple interest as compound or the reverse. They calculate a percentage on the wrong base. They assume that a long-term return will be steady, when real markets move up and down. And they overlook inflation, which reduces the buying power of money over time. The tool pages list the assumptions behind each calculation, and checking them against your real contract or product is the best safeguard.
Using the tools responsibly
These calculators give estimates based on the numbers you enter and standard formulas. They are not financial, tax or legal advice, and real products may include fees, rate changes, taxes and rules that a simple calculator cannot know. Use them to understand, compare and plan, and then confirm important figures with your lender, bank, accountant or tax authority. Calculations run in your browser and are not sent to Dekuz or stored, so you can try different scenarios privately. If you find a result that does not match a trusted source, please tell us through the contact page.
Frequently asked questions about the finance calculators
Do the loan calculators match my bank's figures? They should if the bank uses a reducing balance and charges no extra fees, and any difference usually comes from fees, insurance or rounding, so ask the bank for the annual percentage rate. What is the difference between markup and margin? Markup is profit as a percentage of cost and margin is profit as a percentage of the selling price. Is VAT the same as sales tax? No, VAT is built into prices at each stage, and sales tax is added at the final sale. Can the zakat calculator give a ruling? No, it totals the amounts that you enter, and a scholar should advise on unclear cases. Is my data stored? No.
A short glossary
Principal is the amount borrowed or invested, and interest is the cost of borrowing or the reward for saving. An EMI is a fixed monthly loan payment. Amortisation spreads repayment over time. The annual percentage rate includes fees. Compound interest earns interest on interest. Markup and margin describe profit relative to cost and price. VAT is a value added tax, and sales tax is a tax on retail sales. Break-even is the sales volume at which revenue equals costs. Debt-to-income compares monthly debt payments with gross income. Nisab is the minimum wealth threshold for zakat, and inflation is the general rise in prices.
Getting started: a suggested path
Start with the question that you actually have. If you are borrowing, open the Loan EMI Calculator and test two different terms. If you are saving, open the Savings Goal Calculator and the Compound Interest Calculator. If you sell something, open the Markup Calculator and the Profit Margin Calculator and compare the two percentages for the same product. If you are checking a bill, use the VAT Calculator, the Sales Tax Calculator or the Tip Calculator. If you are comparing jobs, use the Salary to Hourly Calculator, and for housing the Rent Affordability Calculator. Read the worked example on each page before you rely on the result.