$400/mo at 7% for 25 years
$324.0k
$204.0k of that is growth
Do the math.
Your budget, your investments, your tax bill. You can always check how we got the number.
FinnaCalcCalculators
11 calculators. Every one shows its work.
Loan payments, retirement, business runway, what to charge. Try this one right now, no account needed. It runs the same engine as the app, so the number you see here is the number you get there.
An estimate on a steady return, compounded monthly. Real returns vary year to year and can be negative; this is for planning, not a projection of what you will have.
FinnaCalcBudgeting
A budget that lives on your device, not our servers.
Link your bank through Plaid, or just type things in. Set caps on the categories that get away from you, catch the subscriptions you forgot about, watch the savings bar fill. It all stays on your device.
September budget
This one is made up. Yours won’t be.
We show our work
Most money apps hand you a number and expect you to take it on faith. We think that’s backwards. FinnaCalc shows you how every figure was worked out, and when we can’t work something out, we say so on the screen. No guessing, no padding, no invented statistics. It’s your money. You should get to check the math.
The calculator up top, the web app and the iPhone app all share one set of math underneath. The number you saw before signing up doesn’t change after.
FinnaCalcInvesting
Live prices, your actual holdings, ten years of filings.
Watch the market, read the SEC filings for yourself, follow your own cost basis. When you place a trade, it goes through your own brokerage. We never touch the money.
A real session in the iPhone app, recorded August 2026. Prices are from that day.
FinnaCalcTaxes
Know your tax bill before April does.
Filing status, dependents, capital gains, side income, state taxes. There is a proper 1040 engine under here, and we check it against 176 test returns so the estimate is one you can plan around. We never file for you.
What it walks through
- 1Income & filing status
- 2Adjustments & deductions
- 3Credits
- 4Capital gains & dividends
- 5Self-employment
- 6Federal & state estimate
Learn
Short lessons on credit, investing, retirement and taxes, written the way you’d explain them to a friend. And when a lesson raises a question, FinnaBot actually answers it.
Get started
Free to start. Nothing to install.
The calculator above doesn’t even need an account. The rest takes about a minute.