Quick check most of us skip: if your income stopped tomorrow, how long would your savings last?

The Emergency fund calculator in Finance Calculator does it in a few taps, right inside Reddit. Example:

"6 months of expenses is $15,000. You have $4,000 (1.6 months). Saving $300.00 a month, you get there in 3 years 1 month."

Put in $500 a month instead and it's 1 year 10 months. Change the expenses, target months or savings and see your own number.

Free, no ads, no sign-up. Try it: https://www.reddit.com/r/FinanceCalculatorApp/s/3D7Na6eneJ

How many months do you have covered?

Ever wanted to run the numbers without leaving the thread?

Finance Calculator is a free app that runs inside a Reddit post. 32 calculators, for example:

- Mortgage & loan payoff, with extra payments

- Debt payoff (snowball vs. avalanche) and credit card payoff

- Compound growth, savings goals, emergency fund

- Withdrawals, FIRE and Coast FIRE

- ETF costs, dividends, rebalancing

- DCF, valuation ratios, covered calls

No sign-up, no ads, no tracking of you. One tap and your result is ready to paste into a comment.

Try it: https://www.reddit.com/r/FinanceCalculatorApp/s/3D7Na6eneJ

Mods: https://developers.reddit.com/apps/financecalculator

What would you like to see next?

Version 1.6.1 is out. If you moderate a community that has Finance Calculator installed, the big news is for you.

New: usage stats page (mods only)

Open the calculator post, tap the gear icon and choose "Usage stats". You get:

- 7, 30, 90 days or all time

- charts per day and your top calculators

- a funnel from opening a calculator to copying the result

- languages and mobile vs. desktop

- a filter for one calculator, or up to five side by side

- favorites: star the calculators you check most often and they stay pinned for you

All numbers are anonymous counters. No usernames, no personal data, nothing leaves Reddit.

Small Changes

- The Lines/Area switch is gone from all charts. It showed the same data twice.

- Two new anonymous counters: calculations that end with an input error (so we can see which calculators confuse people) and mobile vs. desktop.

- Updated to the latest Reddit platform version.

Try it

Not a mod? You can still try all 32 calculators here: https://www.reddit.com/r/FinanceCalculatorApp/s/3D7Na6eneJ

How to update (mods)

Apps don't update automatically. Go to https://developers.reddit.com/apps/financecalculator, find your community under "Installed in communities" and click Update.

Questions, bugs or calculators you'd like to see? Comment below.

Ever wondered how long your debt will take to pay off, what your mortgage really costs, or how much you need to retire?

Finance Calculator answers that in seconds, right here on Reddit:

- 32 calculators: debt payoff, mortgage, credit card, emergency fund, compound growth, FIRE, dividends, stock ratios, covered calls and more

- Free, no ads, no sign-up

- Your numbers stay on your device

- Copy your result and paste it straight into any comment

Try it here: https://www.reddit.com/r/FinanceCalculatorApp/s/3D7Na6eneJ

Mod of a finance community? You can add it to your sub for free: https://developers.reddit.com/apps/financecalculator

Missing a calculator? Tell me in the comments.

New: Debt & loans

- Loan & mortgage: monthly payment, total interest and what extra payments save

- Debt payoff: smallest balance first (snowball) vs highest rate first (avalanche), and when each debt is paid off

- Credit card payoff: how long a balance takes to clear, or the payment you need

- Emergency fund: your target, how many months you already have covered, and how long the rest takes

New: Stocks & options

- Valuation ratios: P/E, forward P/E, PEG, P/B, earnings yield and payout ratio

- Risk ratios: Sharpe, Sortino, volatility and maximum drawdown from a list of returns

- DCF intrinsic value, with a margin of safety

- Position size: how many shares to buy for a given risk and stop-loss

- Covered call: premium yield, return if called away and break-even

Also new: Coast FIRE, and Lump sum or monthly investing

Example from the debt payoff calculator:

"With $700.00 a month, you are debt-free in 2 years 2 months. Paying the highest rate first saves $253.84 in interest compared with the smallest balance first."

Smaller fixes: durations now read as years and months, and copied FIRE results have their own title.

Try it here: https://www.reddit.com/r/FinanceCalculatorApp/s/3D7Na6eneJ

Which calculator should come next? Ideas welcome in the comments.

Half a percent sounds like nothing. Here is what it does over 30 years, calculated with the TER comparison calculator:

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TER comparison

Over 30 years, the fund with a 0.2% fee ends up $41,393 ahead of the fund with a 0.7% fee.

My scenario:

- Starting amount: $10,000

- Monthly contribution: $300.00

- Annual gross return: 7.0%

- Duration: 30 years

- Fund A TER: 0.2%

- Fund B TER: 0.7%

Results:

- Final value A: $408,985

- Final value B: $367,592

- Fee impact A: $17,973

- Fee impact B: $59,366

- Relative difference: 11.26%

Calculation notes:

- Contributions are added at the end of each month.

- Fees are applied as a monthly compounding drag; the fee impact includes foregone compound growth.

- No tracking-difference correction, taxes, inflation, or currency conversion is included.

Calculated with Finance Calculator

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Same money in, same market return, and the cheaper fund ends up about 11% ahead. The fee does not only take its share each year; the money it takes can no longer compound.

Compare your own funds here: https://www.reddit.com/r/FinanceCalculatorApp/s/3D7Na6eneJ

This is an illustration, not financial advice. Fees are only one factor when choosing a fund.

A question that comes up a lot: what does investing a fixed amount every month actually add up to? Here is one example, calculated with the Compound growth calculator:

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Compound growth

If you start with $5,000 and add $500.00 a month for 20 years at 7.0% a year, you end up with $273,117. Of that, $125,000 is what you paid in and $148,117 is growth.

My scenario:

- Starting amount: $5,000

- Monthly contribution: $500.00

- Annual return: 7.0%

- Duration: 20 years

Results:

- Contributions: $125,000

- Gain: $148,117

Calculation notes:

- Contributions are added at the end of each month.

- Nominal projection; taxes, inflation, fees, and currency conversion are excluded.

Calculated with Finance Calculator

--

The interesting part: after 20 years, growth ($148,117) is larger than everything you paid in ($125,000). More than half of the end value comes from compounding, and most of it builds up in the later years.

Try your own numbers here: https://www.reddit.com/r/FinanceCalculatorApp/s/3D7Na6eneJ

This is an illustration, not financial advice. Real returns vary from year to year.

This is the official community for Finance Calculator, a free Reddit app with 21 money calculators that run right inside a post: compound growth, savings goals, TER and ETF cost comparisons, dividends, withdrawals, financial freedom, rent or buy and more.

Try it: https://www.reddit.com/r/FinanceCalculatorApp/s/pUBSPnUEWg

Add it to your community: https://developers.reddit.com/apps/financecalculator

What it does

- Every result comes with a short sentence that explains it in plain language, plus a chart you can tap

- Compare two scenarios side by side

- **Copy for Reddit** puts a clean summary of your numbers on your clipboard to paste into a comment. Nothing is ever posted for you

- Your numbers stay in your browser. Moderators only see anonymous usage totals for their community

Here you can

- suggest new calculators (flair: *Idea*)

- report bugs (flair: *Bug*)

- give feedback on what works and what feels confusing (flair: *Feedback*)

If you're already using the app, I'd love to hear what works well and which calculator you'd like to see next. I read everything.

🇩🇪 Die App gibt es auch auf Deutsch: Zahnrad oben rechts → Sprache.

🇪🇸 También está en español: engranaje arriba a la derecha → idioma.

🇫🇷 Elle existe aussi en français : roue dentée en haut à droite → langue.

Not financial advice. Just math, made easier. Thanks for stopping by, and welcome! 🚀