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 in your browser, and you do not need an account to use them. By default the numbers stay on that device. Signed-in members can switch on a private copy on their account, and switch it off to delete it.
What runs in your browser means
When you type a figure into these calculators, the arithmetic happens in JavaScript on your machine. By default there is no request carrying that figure to a server. When you come back on the same browser, the values are still there because they were written to your browser's local storage. If you turn on Save to my account, a private copy is stored on your account so the numbers follow you to another device. Only you can read that copy.
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 figures being sent to us unless you turn on Save to my account. 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. Create an account if you want the numbers on another device, or if you want the lessons, quizzes and games. The arithmetic itself does not require an account.
What that means practically
- On this device only, unless you turn on Save to my account.
- Clearing your browser data clears the device copy.
- Private or incognito windows will not retain the device copy after you close the window.
- Other members cannot read an account copy. Turning the switch off deletes it.
Common questions
Do you store the numbers I enter into the calculators?
By default they stay in your browser on that device. If you are signed in, you can switch on Save to my account to keep a private copy on your account. Only you can read it.
Do I need an account to use the calculators?
No. The Budget Tools work while signed out. An account is only needed if you want the numbers on another device, or for lessons, quizzes and games.
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.