Free finance calculators — loan, mortgage, compound interest, savings
Money math you can check yourself: loan and mortgage payments with the real amortization, compound-interest and savings projections, car loans, retirement and inflation, sales tax and discounts. Each one shows how the number is built — principal, rate, term — so you can compare offers instead of trusting a single quote. No signup, no data leaves your browser.
Tip Calculator (with bill split for groups)
Calculate tip and split a restaurant bill across any number of people. Quick presets for common tip percentages.
Compound Interest Calculator (with monthly contributions)
See how an investment grows over time with compounding interest and optional monthly contributions. Customizable compounding frequency.
Loan Calculator (monthly payment, interest, total cost)
Calculate the monthly payment for any fixed-rate loan, plus total amount paid and total interest over the life of the loan.
Sales Tax / VAT Calculator (add tax or extract from total)
Add sales tax to a pre-tax amount or extract the tax from a tax-inclusive total. Works for any tax rate (sales tax, VAT, GST).
Discount Calculator (with optional sales tax)
Calculate the final price after a percentage discount, plus optional sales tax. See how much you saved at a glance.
Mortgage Calculator (PITI: principal, interest, tax, insurance)
Calculate the full monthly mortgage payment including principal, interest, property tax, insurance, PMI (if applicable), and HOA fees.
Markup Calculator (cost to sell price + margin)
Calculate sell price, gross profit, and gross margin from cost and markup percentage. Distinguishes markup vs margin clearly.
Free Unit Price Calculator 2026 — Cost per Gram, Ounce or Count
Free unit price calculator. Enter prices and quantities (g, oz, count, fl oz) to compare cost per unit instantly. Find the cheaper option at the store.
Credit Card Validator (Luhn check + brand detection)
Validate a credit card number's checksum (Luhn algorithm) and detect the issuing brand. Browser-only — your card number never leaves your device.
Savings Goal Calculator (time to reach target)
Find out how long it takes to reach a savings goal given a starting balance, monthly contribution, and annual return.
Salary Converter (hourly, daily, weekly, monthly, annual)
Convert pay between hourly, daily, weekly, monthly, and annual rates. Useful for comparing job offers and contractor rates.
Retirement Calculator (compound projection + inflation-adjusted)
Project your retirement savings with monthly contributions, expected return, and inflation. Shows nominal balance, today-dollar value, and 4%-rule monthly income.
Simple Interest Calculator (I = P × r × t)
Calculate simple interest on a principal amount given an annual rate and time. Returns interest earned and total balance.
Car Loan Calculator (monthly payment + total interest)
Calculate monthly auto-loan payment, total interest, and total cost. Includes down payment and trade-in value adjustments.
Crypto Profit Calculator (with exchange fees)
Calculate crypto trading profit, ROI, and fee impact. Enter amount held, buy price, sell price, and exchange fee % — get net profit after both buy and sell fees.
Stock Profit Calculator (with dividends + taxes)
Calculate stock trade profit including buy/sell commissions, dividends received, and capital-gains tax. Returns net after-tax profit and ROI.
Inflation Calculator (purchasing power over time)
See how inflation erodes purchasing power: future cost of today's money, plus today's value of a future amount.
Emergency Fund Calculator (3-12 months of expenses)
Calculate the size of an emergency fund (3, 6, 9, or 12 months of expenses) and how long it takes to build at your savings rate.
Income Tax Bracket Calculator (JP / US)
Calculate income tax owed using progressive brackets. Japan, US single, and US married-filing-jointly. Returns total tax, effective rate, marginal rate, and per-bracket breakdown.
VAT / Sales Tax Calculator (international rates)
Add or remove VAT/GST/sales tax. Quick presets for Japan, UK, EU countries, Australia, Canada, China.
ROI Calculator (Return on Investment + Annualized)
Calculate return on investment (ROI) % and annualized return for any holding period. Works for any investment: stocks, real estate, business, side projects.
Fuel Cost Calculator (trip cost + per-person split)
Calculate fuel cost for any trip from distance, fuel efficiency (MPG or km/L), and fuel price. Optional split between passengers.
Net Worth Calculator (assets minus liabilities)
Calculate net worth: total assets minus total liabilities. Categorized inputs for cash, investments, retirement, real estate, vehicles, mortgage, loans, credit cards.
Rule of 72 Calculator (doubling time / required rate)
Estimate how long an investment takes to double using the Rule of 72, or solve for the rate needed to double in a given period. Compares against exact compound math.
CAGR Calculator (Compound Annual Growth Rate)
Calculate compound annual growth rate from start value, end value, and number of years. Returns CAGR %, total return %, and multiplier.
Loan Amortization Schedule (full or yearly)
Generate a full month-by-month amortization schedule for any fixed-rate loan. Shows principal/interest split per payment, ending balance, and a CSV export.
Debt-to-Income (DTI) Ratio Calculator
Calculate your front-end and back-end debt-to-income ratios from monthly income and debt payments. See how lenders categorize you.
Life Insurance Needs Calculator (DIME formula)
Calculate how much life insurance you actually need using the DIME method: Debt + Income replacement + Mortgage + Education.
ROAS Calculator (Return on Ad Spend)
Calculate ROAS from revenue and ad spend, plus the profit-adjusted ROAS using gross margin. See breakeven multiple instantly.
Credit Utilization Calculator (per-card and overall)
Calculate your overall credit utilization ratio and per-card ratios. See exactly how lenders score your card balances against limits.
Annuity Payout Calculator (fixed-period)
Calculate the regular payout from an annuity given principal, interest rate, and payout period. Supports monthly or annual distributions.
Mortgage Refinance Calculator (break-even + lifetime savings)
Compare your current mortgage against a refinance offer. See monthly payment change, lifetime interest savings, and the break-even month after closing costs.
Lease vs Buy Calculator (car, total cost over hold period)
Compare leasing and financing a car over your actual hold period. See which is cheaper after factoring loan interest, monthly cash out, and resale value.
Cost of Living Comparison (city to city, equivalent salary)
See what salary you need in a target city to maintain the same lifestyle. Weighted by overall and rent indexes from sources like Numbeo.
Expense Ratio Calculator — True Cost of Investment Fees
See how much expense ratios actually cost you over decades. Compare a 1% fee vs a 0.05% index fund — the gap can exceed your initial investment.
Japan Price Comparison — Rakuten Ichiba
Search and compare product prices on Rakuten Ichiba, sorted cheapest first.
FIRE Number Calculator — Financial Independence Retire Early
Calculate your FIRE number — the total savings needed to retire early. Enter annual expenses, withdrawal rate, and current savings to see how many years to financial independence.
Break-Even Calculator — Units, Revenue & Contribution Margin
Calculate how many units you need to sell to cover your costs. Enter fixed costs, price per unit, and variable cost per unit to find your break-even point instantly.
Electricity Cost Calculator — kWh & Bill Estimator
Enter an appliance's wattage, daily hours of use, and your electricity rate to calculate daily, monthly, and yearly electricity costs.
Meeting Cost Calculator — Real Cost of Meetings
Calculate the true dollar cost of any meeting by attendees, annual salary, and duration.
Paycheck Calculator — 2024 US Federal Take-Home Pay
Calculate your US take-home pay after federal tax, FICA, and state tax estimate. Supports all filing statuses and pay frequencies.
Debt Payoff Calculator — Pay Off Date & Interest
Find your debt-free date or required monthly payment using standard amortization. Works for credit cards, personal loans, and any fixed-rate debt.
Bill Split Calculator — Split Bills & Tip Evenly
Split any restaurant bill evenly or by custom shares. Calculates tip, total, and per-person amount instantly.
House Affordability Calculator — How Much Can You Afford?
Find the maximum home price you can afford using the 28/36 rule, your income, debts, and down payment.
Profit Margin Calculator – Margin & Markup
Calculate profit, profit margin, and markup from cost and revenue.
Sales Commission Calculator - Commission & Net Pay
Calculate sales commission and net amount from a sale value and rate.
Down Payment Calculator for Home Buyers
Calculate your home down payment and remaining loan amount instantly.
Effective Annual Rate Calculator (EAR / APY)
Find the true yearly rate after compounding from a nominal rate.
Cost per Use Calculator
Find out what each use of an item really costs.
Future Value Calculator - Compound Interest FV
Calculate the future value of a lump sum with compound interest.
Present Value Calculator (PV of Future Money)
Calculate the present value of a future amount discounted at a given rate.
Overtime Pay Calculator
Calculate your overtime pay from hours, hourly rate and multiplier.
SIP Calculator — Mutual Fund Maturity Value
Estimate the future value of your monthly SIP investments.