Topical hub
Free Finance Calculators
Loans, mortgages, investing, tax and business maths in one connected hub.
110 calculators across 7 semantic clusters — free forever, instant results, downloadable PDF reports.
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- Unlimited Calculations
- Instant Reports
Finance calculators translate money decisions into numbers you can compare. Every tool in this hub works on the same underlying ideas — a principal amount, a rate applied over time, and a schedule of payments or contributions — so learning one model makes the next one easier to read.
The hub is organised the way lenders, accountants and investors actually think: borrowing on one side, growing money on the other, and the tax and business layer that connects them. A mortgage payment, a car lease, a credit card payoff plan and a business loan all reduce to the same amortisation formula; a retirement projection, a 401(k) balance and a compound interest run all reduce to future value.
Rates are the pivot point in almost every calculation. A nominal rate tells you what is quoted, an effective rate tells you what you actually pay or earn after compounding, and APR folds fees into the comparison. When two products look similar, it is nearly always the rate definition, the compounding frequency or the term length that separates them.
Time is the second lever. Extending a loan term lowers the payment and raises total interest; extending an investment horizon does the reverse, letting compounding do the work. Most of the finance tools here expose both so you can see the trade-off instead of guessing at it.
Use the clusters below to move through a decision rather than a single number: price a mortgage, then check the down payment, property tax and rent-vs-buy comparison; project retirement savings, then test the withdrawal rate, tax treatment and inflation drag against it.
Calculator directory
Mortgages & Home Loans
Buying, financing and refinancing property.
Free Mortgage Calculator
Estimate your monthly mortgage payment, total interest, and payoff schedule.
Free Refinance Calculator
Compare current vs. refinanced mortgage payments and break-even.
Free Mortgage Payoff Calculator
See how extra monthly payments shorten your mortgage.
Free FHA Loan Calculator
Estimate FHA mortgage payment with MIP.
Free VA Loan Calculator
VA loan payment with funding fee.
Free Property Tax Calculator
Estimate annual property tax from assessed value and mill rate.
Free Down Payment Calculator
Down payment amount and PMI implications from home price and percent.
Free Rent vs Buy Calculator
Compare total costs of renting versus buying over a horizon.
Free Home Equity Calculator
Estimate available home equity and HELOC borrowing power.
Free Real Estate Calculator
Total monthly cost of home ownership (PITI + HOA).
Free Real Estate Investment Calculator
Cash flow and returns on an income property.
Loans & Debt Payoff
Instalment borrowing, credit cards and payoff strategy.
Free Auto Loan Calculator
Monthly car payment from price, down payment, trade-in, and sales tax.
Free Loan Calculator
Compute the fixed monthly payment on any amortizing loan.
Free Personal Loan Calculator
Monthly payment and total cost for a personal loan.
Free Business Loan Calculator
Payment and interest cost for a business term loan.
Free Student Loan Calculator
Estimate monthly payment and total interest on a student loan.
Free Boat Loan Calculator
Estimate monthly payments on a boat loan.
Free RV Loan Calculator
Monthly payment for a recreational vehicle loan.
Free Lease Calculator
Estimate the monthly payment for a vehicle lease.
Free Amortization Calculator
Year-by-year principal, interest, and remaining balance schedule.
Free APR Calculator
True annual percentage rate on a loan with fees.
Free Debt Payoff Calculator
Months to pay off a debt at a fixed monthly payment.
Free Debt Consolidation Calculator
See if consolidating debts into one loan lowers your payment.
Free Credit Card Payoff Calculator
Months to pay off a credit card balance at a fixed monthly payment.
Free Invoice Late Fee Calculator
Late payment fee and total amount owed on an overdue invoice.
Free Equipment Lease vs Buy Calculator
Compare total cost of leasing vs buying business equipment.
Free Loan Extra Payment Calculator
Interest and time saved by paying extra on a loan (EMI).
Free Allowance / Pocket Money Calculator
Weekly allowance based on age, chores and savings split.
Investing & Retirement
Growing capital and planning for withdrawal.
Free Compound Interest Calculator
Project the future value of savings with compounding and periodic contributions.
Free Simple Interest Calculator
Interest earned or owed under simple (non-compounding) interest.
Free Investment Calculator
Project future value of a lump sum plus regular contributions.
Free Retirement Calculator
Project retirement balance and check the 4% withdrawal rule.
Free Roth IRA Calculator
Project tax-free Roth IRA balance at retirement.
Free 401(k) Calculator
Project a 401(k) balance including employer match.
Free CD Calculator
Certificate of deposit interest and maturity value.
Free Savings Calculator
Monthly deposit needed to reach a savings goal by a target date.
Free ROI Calculator
Return on investment as a percentage plus annualized rate.
Free Bond Calculator
Price a bond from face value, coupon, yield, and maturity.
Free Annuity Calculator
Future value of an ordinary annuity.
Free 529 Plan Calculator
Project 529 college savings growth.
Free Social Security Calculator
Estimate monthly Social Security retirement benefit.
Free College Cost Calculator
Projected 4-year college cost with tuition inflation.
Free Payback Period Calculator
How long an investment takes to repay itself.
Free Dividend Calculator
Dividend income, yield and reinvested growth.
Free Savings Goal Calculator
Monthly amount needed to hit a savings target.
Free IRR Calculator
Approximate internal rate of return for level annual cash flows.
Free NPV (Net Present Value) Calculator
Discounted cash flow value of an investment over 5 years.
Free Annuity Payout Calculator
Periodic payment a lump sum can sustain.
Free Bond Yield to Maturity Calculator
Approximate YTM for a coupon bond.
Free CAGR Calculator
Compound annual growth rate between two values.
Free Cost Basis / Average Down Calculator
Blended average cost after adding to a position.
Free Crypto Profit Calculator
Profit/loss on a cryptocurrency trade, after fees.
Free Dollar Cost Averaging Calculator
Shares and average cost from periodic fixed investments.
Free Dividend Reinvestment (DRIP) Calculator
Portfolio growth with dividends reinvested vs taken as cash.
Free Emergency Fund Calculator
Target cash cushion based on monthly expenses.
Free Expense Ratio Impact Calculator
Long-term cost of fund fees on portfolio growth.
Free FIRE Number Calculator
Portfolio size needed for financial independence.
Free Future Value Calculator
What a lump sum plus contributions grows to.
Free Margin Trading Calculator
Leveraged return and margin call price.
Free Mining Profitability Calculator
Daily/monthly profit from crypto mining.
Free Options Break-Even Calculator
Stock price needed to break even on a call or put.
Free Portfolio Rebalance Calculator
Trades needed to return to target stock/bond allocation.
Free Present Value Calculator
What a future sum is worth today.
Free Rule of 72 Calculator
Quick estimate of years to double your money.
Free Staking Rewards Calculator
Compounded staking income over time.
Free Stock Profit Calculator
Profit or loss on a stock trade, after fees.
Free Treasury Bill Calculator
Discount yield and investment return on a T-bill.
Taxes & Income
Pay, withholding and tax liability.
Free Salary Calculator
Convert between hourly, weekly, monthly, and annual pay.
Free Take-Home Pay Calculator
Estimate net pay after federal, FICA, and state deductions.
Free Income Tax Calculator
Estimated US federal income tax using 2024 brackets.
Free Sales Tax Calculator
Add or reverse sales tax from a pre- or post-tax price.
Free Estate Tax Calculator
Estimate federal estate tax (2024).
Free Overtime Pay Calculator
Weekly pay with overtime and double-time hours.
Free Commission Calculator
Commission earned on sales, with base pay.
Free Gross to Net Pay Calculator
Estimate take-home pay after taxes and deductions.
Free Hourly to Salary Calculator
Convert an hourly wage into annual, monthly and weekly salary.
Free Payroll Tax Calculator
Employer and employee FICA-style payroll tax estimate (US).
Free Self-Employment Tax Calculator
SE tax on net self-employment earnings (US 15.3% rule).
Free Capital Gains Tax Calculator
Estimated tax owed on short- or long-term gains.
Free Inheritance Split Calculator
Divide an estate among heirs by equal or custom shares.
Free Marginal vs Effective Tax Rate Calculator
US federal tax owed, marginal bracket, and effective rate.
Free Tithing / Zakat Calculator
Charitable giving amount from income or wealth.
Business & Accounting
Unit economics, margins and company metrics.
Free VAT Calculator
Add or reverse Value Added Tax from net or gross price.
Free Discount Calculator
Sale price and savings from a list price and discount percent.
Free Margin Calculator
Profit margin, markup, and selling price from cost and revenue.
Free Depreciation Calculator
Straight-line depreciation of an asset over its useful life.
Free Break-Even Calculator
Units and revenue needed to cover costs.
Free Burn Rate & Runway Calculator
Monthly cash burn and months of runway remaining.
Free Business Valuation Calculator
Estimate business value using an earnings multiple (SDE/EBITDA).
Free Cash Flow Calculator
Net cash flow from operating, investing and financing activities.
Free Churn Revenue Calculator
Revenue lost to customer churn and net revenue retention.
Free Cost Per Acquisition Calculator
Cost per lead and per converted customer across a funnel.
Free Customer Acquisition Cost Calculator
CAC from total sales & marketing spend and new customers won.
Free Customer Lifetime Value Calculator
CLV from average order value, purchase frequency and margin.
Free EBITDA Calculator
Earnings before interest, taxes, depreciation & amortization.
Free Freelance Rate Calculator
Hourly rate needed to hit a target income as a freelancer.
Free Gross Profit Calculator
Gross profit and gross margin from revenue and COGS.
Free Inventory Turnover Calculator
How many times inventory is sold and replaced per year.
Free Invoice Discount Calculator
Early-payment discount savings (e.g. 2/10 net 30 terms).
Free Margin vs Markup Calculator
Convert between profit margin and markup percentages.
Free Markup Calculator
Selling price from cost and desired markup percentage.
Free Sales Forecast Calculator
Project future sales using a constant growth rate.
Free Working Capital Calculator
Working capital and current ratio from balance sheet items.
Budgeting & Everyday Money
Household cash management and small money decisions.
Free Tip Calculator
Split a restaurant bill with tax and tip across any number of people.
Free Currency Calculator
Convert between currencies using a manual exchange rate.
Free Budget Calculator
50/30/20 monthly budget split from take-home pay.
Free Rental Property Calculator
Cash flow, cap rate, and cash-on-cash return for a rental.
Free Net Worth Calculator
Assets minus liabilities, at a glance.
Free Cap Rate Calculator
Capitalization rate on a rental property.
General Finance
Broader money tools that span several finance topics.
Key concepts in finance calculators
- Principal
- The amount borrowed or invested before interest is applied. Every amortisation and future-value formula starts here.
- Interest rate
- The periodic cost of borrowing or the return on capital, quoted annually and divided by the compounding frequency inside the maths.
- APR
- Annual percentage rate — the interest rate plus lender fees expressed as one comparable annual figure.
- Amortisation
- The schedule that splits each level payment into interest first and principal second, front-loading the interest.
- Compounding
- Interest earning interest. Frequency (monthly, quarterly, annual) changes the effective outcome materially over long horizons.
- Future value
- What a balance grows to after a number of periods at a given rate, with or without recurring contributions.
- Present value
- What a future sum is worth today once discounted at a chosen rate — the basis of NPV and IRR.
- Effective tax rate
- Total tax divided by total income, distinct from the marginal rate applied to the last dollar earned.
- Cash flow
- Money actually moving in and out over a period, as opposed to accounting profit.
- Equity
- Asset value minus the debt secured against it — the driver behind home equity and net worth tools.
How this topic works
How lenders price a loan
A lender starts with a benchmark cost of funds, adds a credit spread for the risk you represent, and adds an origination margin. That total becomes your nominal rate. Fees are then folded into APR so two offers can be compared on one number. The payment itself comes from the standard amortisation formula: payment = P × r / (1 − (1 + r)^−n), where r is the periodic rate and n the number of payments. Because interest is charged on the outstanding balance, early payments are mostly interest and later payments mostly principal — which is why extra principal payments made early save disproportionately more.
Why compounding frequency matters
A 6% annual rate compounded monthly produces an effective annual rate of about 6.17%, not 6%. Over one year the difference looks trivial; over thirty years of contributions it becomes a significant share of the final balance. Savings, CD, investment and retirement calculators in this hub all expose compounding frequency for that reason, and the rule of 72 gives a fast sanity check: divide 72 by the rate to approximate the doubling period.
Nominal versus real returns
Inflation erodes purchasing power, so a 7% nominal return during 3% inflation is roughly a 4% real return. Long-horizon planning — retirement, college saving, FIRE targets — should be run in real terms or with an inflation adjustment applied at the end, otherwise the projected balance overstates what it will actually buy.
Marginal versus effective tax
Progressive tax systems apply different rates to different income bands. Your marginal rate is the rate on the next dollar and drives decisions about deductions, bonuses and retirement contributions; your effective rate is total tax over total income and describes your actual burden. Confusing the two is the most common error in take-home pay and self-employment tax estimates.
Reading a business model in numbers
Business calculators sit on three relationships: unit economics (price minus variable cost = contribution margin), the break-even point (fixed costs divided by contribution margin), and the payback or return horizon (NPV, IRR, CAC versus lifetime value). A model that clears break-even but never repays acquisition cost is not yet a business, which is why these tools link to each other rather than standing alone.
Frequently asked questions
What is the difference between interest rate and APR?
The interest rate is the pure cost of borrowing the principal. APR adds lender fees, points and certain closing costs, expressed as an annual percentage, so it is the fairer number when comparing two loan offers with different fee structures.
Which finance calculator should I start with?
Start with the decision, not the tool. For a home purchase begin with the mortgage calculator, then the down payment and property tax tools. For long-term saving begin with compound interest, then move to retirement, 401(k) or Roth IRA projections.
How accurate are these finance calculators?
The mathematics is exact for the inputs given. Real-world accuracy depends on your assumptions — rate changes, fee structures, tax brackets and inflation are estimates, so treat outputs as well-structured projections rather than quotes.
Why does extending a loan term increase total interest?
Interest accrues on the outstanding balance each period. A longer term means the balance stays high for longer, so even at the same rate you pay interest across more periods, raising the lifetime cost while lowering the monthly payment.
Should I use nominal or inflation-adjusted returns for planning?
For anything beyond about five years, use inflation-adjusted (real) figures. Nominal projections overstate purchasing power, especially for retirement and college-cost planning where horizons run for decades.
What is a good rule of thumb for savings rate?
Common guidance is 15–20% of gross income toward long-term saving, but the savings goal and FIRE number calculators let you replace the rule of thumb with a target-driven figure based on your own spending and horizon.
How do business valuation and cash flow calculators relate?
Valuation methods discount future cash flows back to today, so cash flow is the input and valuation the output. Running the cash flow model first makes the valuation assumptions explicit instead of hidden.
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