Finance & Everyday Math Calculators
Percentages, tips, discounts, tax, markup, pay, and interest — the everyday money math, worked out clearly. General information, not financial advice.
16 free calculators · updated June 2026
Percentage Calculator
The three everyday percentage questions in one tool — X% of Y, X is what % of Y, and percent change.
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Tip Calculator
Tip, total, and the per-person split — pick 15/18/20/25% or enter your own.
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Discount Calculator
The sale price after a percentage off — with optional sales tax applied after the discount.
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Sales Tax Calculator
Add sales tax to a price, or back it out of a tax-included total to find the pre-tax amount.
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Markup / Margin Calculator
Price, profit, markup, and margin from your cost — set the price by markup %, margin %, or a target price.
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Hourly to Salary Calculator
Convert an hourly rate to annual, monthly, and weekly pay — or a salary back to an hourly rate.
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Bill Split Calculator
Split a group bill evenly with tip — the per-person number front and center.
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Simple Interest Calculator
Interest and total from principal, rate, and time — simple interest, not compound.
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Compound Interest Calculator
Growth with interest on interest — principal, rate, time, compounding frequency, and optional monthly deposits.
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Loan Payment Calculator
Monthly payment, total interest, and total paid on any fixed-rate loan — auto, personal, or student.
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Car Loan Calculator
Monthly auto payment from price, down payment, trade-in, rate, term, and tax — with the amount financed.
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Savings Goal Calculator
How much to save each month to hit a goal — or how long a fixed deposit takes — with compound growth.
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ROI Calculator
Return on investment and net profit — plus the annualized rate when you add a holding period.
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Inflation Calculator
What inflation does to buying power — and the future dollars needed to match today’s value.
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Take-Home Pay Calculator
A rough take-home estimate per paycheck from gross salary, pay frequency, and a combined deduction rate.
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Break-Even Calculator
The units and revenue to cover your costs — fixed costs over the contribution margin per unit.
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