FinlyCalc

Free finance calculators that just work

FinlyCalc is a growing set of fast, focused finance calculators that run entirely in your browser. Mortgages, savings, loans, and more. One job per tool, no signup, and nothing you type ever leaves your device.

No signup Runs in your browser Free forever Updated for 2026

Tools

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Mortgage Calculator
Monthly payment, full amortization schedule, and extra payment savings.
Live
💸
Loan Calculator
Auto, personal, and student loan payments with a payoff timeline.
Live
📈
Compound Interest
See how savings and investments grow over time with regular contributions.
Live
🔄
Refinance Calculator
Compare your current loan to a new rate and see the break even point.
Live
🚗
Auto Loan Calculator
Monthly car payment with trade in, sales tax, and total interest.
Live
🎯
Savings Goal Calculator
Find the monthly amount you need to reach a target by a set date.
Live
🏖️
Retirement Calculator
Project your nest egg and see if your savings rate is on track.
Live

Guides

Plain-English explainers for the money questions behind each calculator. No jargon, no signup.

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How much house can I afford?
The 28/36 rule turned into a real home price, with a worked example.
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How compound interest works
Interest on interest, the rule of 72, and why time wins.
🔄
Should I refinance?
The break even test that answers it in one line.
🏖️
How much do I need to retire?
The 25x rule and the 4 percent rule, applied to your gap.
📚
All guides →
The full FinlyCalc guide library.

Why FinlyCalc

Built for one job

Each tool answers a single question well, so you get to the answer fast and the page stays easy to read.

Private by design

Every calculation happens in your browser. Your numbers are never sent to a server or stored anywhere.

Always current

Formulas and rates are reviewed each year, so the result you see reflects the current year.

Free, no account

No login, no paywall, no email required. Open a tool and start.

Common questions

Are the calculators accurate?

Each tool uses the standard financial formula for its job: monthly amortization for loans and mortgages, the compound growth formula for savings and investments, and the break even method for refinancing. Results are precise estimates for planning. They are not personalized financial advice.

Is my financial data private?

Yes. Every calculation runs entirely in your browser using JavaScript. The numbers you enter are never sent to a server, never stored, and never shared. You can even use the tools offline once the page has loaded.

Do I need to sign up or pay?

No. There is no account, no email, and no paywall. Every calculator and every guide is free to use as often as you like.

Are the figures current for 2026?

Yes. The formulas and the default rates in each tool are reviewed every year, so the result you see reflects current figures rather than an outdated default.

Can I use FinlyCalc on my phone?

Yes. Every page is built to work in any modern browser on desktop, tablet, or phone, with no app to install.

Do you give financial advice?

No. FinlyCalc gives you clear numbers so you can understand your options, but the results are estimates for planning. For a decision that affects your money, speak with a qualified professional.