JagInsights › Money guides › Private budget calculator
Budget calculators that keep your numbers on your device
Most free budget calculators are lead-generation. You enter your income, your debts and your rent, and the real product is you.
JagInsights' nine budget calculators run entirely in your browser. The numbers you type are never sent to us — they are saved to your own device's local storage, and clearing your browser data deletes them. You do not need an account to use them.
What runs in your browser means
When you type a figure into these calculators, the arithmetic happens in JavaScript on your machine. There is no request carrying that figure to a server, because there is no server-side calculation. When you come back, the values are still there because they were written to your browser's local storage — a per-site store on your own device that we cannot read remotely.
The nine calculators
- 50/30/20 split — needs, wants and savings against take-home pay.
- Subscriptions — monthly and annual totals, and what they are as a share of income.
- Paycheck — gross to net, with pre-tax deductions and an effective tax rate.
- Emergency fund — how long your savings would actually cover essentials.
- Net worth — assets minus liabilities.
- Rent vs buy — monthly cost of ownership against renting.
- Credit card payoff — what a balance costs and how long it takes to clear.
- Investing growth — compounding over time with regular contributions.
- Crypto exposure — what a drawdown would do to your position.
Being precise about the claim
Worth stating exactly, because privacy claims are usually overstated. The pages themselves are served over the network like any website, and the site loads fonts from Google, which means Google's servers see the request for the font file. What does not happen is your financial figures being transmitted anywhere. There is no analytics on this site, no advertising, and no third-party tracking scripts — not as a policy position, but because that code does not exist in the site.
No account needed
The calculators work signed out. An account exists for the lessons, quizzes and games, where progress needs somewhere to live — but if all you want is the arithmetic, you never have to create one.
What that means practically
- Your figures do not sync between devices, because they never leave the one you typed them on.
- Clearing your browser data clears them.
- Private or incognito windows will not retain them after you close the window.
- Nobody at JagInsights can see them, including us.
Common questions
Do you store the numbers I enter into the calculators?
No. They are held in your browser's local storage on your own device and are never transmitted to JagInsights.
Do I need an account to use the calculators?
No. The Budget Tools work while signed out. An account is only needed for lessons, quizzes and games, where progress has to be saved.
Will my figures sync across devices?
No — and that is the trade-off of keeping them local. They exist only on the device where you typed them.
Is there any advertising or tracking on the site?
No. There is no advertising code, no analytics and no third-party tracking scripts anywhere in the site.
What happens if I clear my browser data?
The saved values are deleted, because that is where they live. There is no server copy to restore from.
Educational information only — this is not financial advice, and JagInsights is not a financial adviser, broker or lender. See our Terms and Privacy Policy.