Finance Tools
Mortgage, compound interest, sales tax, and tip calculators. Everyday money math computed instantly in your browser — nothing uploaded, fully private.
Compound Interest Calculator
Calculate compound interest with monthly contributions. See future value, interest earned, and yearly growth - free, instant, 100% private.
Mortgage Calculator
Calculate your monthly mortgage payment with taxes, insurance, PMI, and extra payments. Full amortization schedule, free and private.
Sales Tax Calculator
Add or remove sales tax from any price. Enter net or gross amount and rate to get tax, total, and pre-tax price - free and 100% private.
Tip Calculator
Calculate tips and split the bill in seconds. Choose a percentage, set the party size, see per-person totals - free and 100% private.
Everyday money math, solved in seconds. These finance calculators cover the questions people run into most often: what a home really costs per month once principal, interest, taxes, insurance, and PMI are counted; how fast compound interest grows a balance; what a price becomes once sales tax is added (or how much tax is hidden inside a tax-inclusive price); and how to split a bill with a fair tip. Every calculation runs locally in your browser, so your numbers never leave your device.
How to Use
Use the mortgage calculator when you are buying a home or comparing loan offers: enter the price, down payment, term, and rate, and it shows the full monthly payment — principal & interest plus property tax, insurance, HOA, and PMI that drops off automatically at 80% LTV — along with the amortization schedule and the effect of extra payments. Use the compound interest calculator when you want to see how an initial deposit plus regular monthly contributions grows over years at a given annual rate — savings accounts, CDs, or long-term investment projections. Use the sales tax calculator at checkout time: enter a net price to add tax, or a shelf price to back out the tax already included. Use the tip calculator after a meal or a service: enter the bill, pick a percentage, and split the total across the whole party, with optional rounding so each person pays a whole amount.
Tips & Best Practices
The four finance tools share a calculator skeleton — type numbers, read a result — but they answer different questions. The mortgage calculator is a payment tool: it turns a price and a rate into the true monthly cost of a home, breaking it into principal, interest, taxes, insurance, and PMI, and showing every year of the payoff. The compound interest calculator is a projection tool: it simulates month-by-month growth over years and shows how much of the final balance came from contributions versus interest. The sales tax calculator is a conversion tool: it converts between net and gross prices in either direction, which is why it offers an add mode and a remove mode. The tip calculator is a splitting tool: its job is fairness in a group — per-person amounts, not growth over time. A practical pairing: the mortgage calculator tells you what borrowing costs, compound interest tells you what saving a little each month becomes in ten years, and the tip and sales tax calculators handle the money you spend today.