Finance Calculators

Free finance calculators — loan, mortgage, car loan, compound and simple interest, savings goal, retirement, debt payoff, ROI, inflation, salary and fuel cost.

100% Browser-Based Local Processing

Finance & Money 12

Loans, savings and pay. Estimates that show their working — not financial advice.

More calculators

The other eight groups, and the full index of all 55.

Privacy Focused

🔒 Local Processing. Your numbers never leave your device.

Instant Results

🌐 Fully Client-Side. Runs instantly in your browser.

No Signup

⚡ No accounts. No API keys. Just open and use.

Browser Based

🚀 No installs, no sign-ups, no server round-trip.

What are the Finance Calculators?

Randomly's finance calculators estimate the numbers behind borrowing, saving and earning — monthly loan and mortgage payments, compound and simple interest, savings goals, retirement projections, debt payoff order, ROI, inflation, hourly pay and fuel cost. Each shows its formula, runs in your browser, and is an estimate rather than financial advice.

Twelve calculators for money questions, from the very common — what would the monthly payment on this loan be — to the ones people put off, like how long it will actually take to clear a set of debts.

These are the tools where privacy matters most, so it is worth being explicit: your salary, your loan balance and your retirement savings are typed into a page that never sends them anywhere. The calculation happens in your browser. Nothing is uploaded, nothing is stored, and there is no account for it to be attached to.

They are also the tools where honesty about limits matters most. Each one states the assumptions it makes and what it leaves out, because a payment figure that quietly ignores fees and rate changes is worse than no figure at all.

Finance Calculators in action

The Finance & Money calculator grid on Randomly in dark mode — 12 cards: Loan, Mortgage, Car Loan, Compound Interest, Simple Interest, Savings Goal, Retirement, Debt Payoff, ROI, Inflation, Salary to Hourly, Fuel Cost
Tool grid (12 calculators)
The Finance & Money calculators on a phone, the 12 cards stacked in a single column
Mobile (stacked grid)

Good to know

  • Your figures never leave the browser. Salary, balances and rates are calculated locally. Nothing is uploaded, logged or stored — unlike most cloud finance tools, which require an account.
  • Assumptions are stated, not hidden. Every calculator says what it models and what it ignores, so you can judge how much weight the number deserves.
  • The formula is shown. You can check the arithmetic, or rebuild it in a spreadsheet if you want to extend it.
  • Estimates, not advice. These are math tools for comparing scenarios. They do not know your full circumstances, and they are not a substitute for a qualified professional.

Frequently Asked Questions

What finance calculators are in this group?

Twelve: Loan, Mortgage, Car Loan, Compound Interest, Simple Interest, Savings Goal, Retirement, Debt Payoff, ROI, Inflation, Salary to Hourly, and Fuel Cost. They cover borrowing, saving, investing and earning, and each is a focused tool rather than a mode inside a larger product.

Are these results financial advice?

No. Every calculator here is a math tool that applies a standard formula to the numbers you enter. They use simplified models, generally ignore fees, taxes and rate changes, and know nothing about your wider circumstances. Use them to compare scenarios and get a sense of scale, and consult a qualified financial professional before making a decision.

Is my salary or loan balance sent anywhere?

No. All twelve calculators run entirely in your browser. The figures you enter are never transmitted to a server, never written to a database, and are gone as soon as you close the tab. There is no signup, so there is no account for a calculation to be attached to.

What is the difference between the Loan and Mortgage calculators?

Both amortise a debt, but the Mortgage Calculator is built around a property purchase — it handles the deposit and the loan-to-value relationship and presents a long schedule. The Loan Calculator is general-purpose, suits shorter terms, and makes extra payments easier to model. For a vehicle specifically, the Car Loan Calculator adds the trade-in and down-payment handling that purchase usually involves.

Does the mortgage calculator include taxes, insurance and fees?

It calculates principal and interest. Property taxes, insurance, service charges and arrangement fees vary so much by location and lender that including a generic figure would make the result look more precise than it is. The page says so explicitly. Treat the output as the loan repayment component, not the full monthly cost of owning.

How does the debt payoff calculator decide the order?

It supports both common strategies. Avalanche pays the highest interest rate first, which costs the least overall. Snowball pays the smallest balance first, which clears individual debts sooner and is easier to stick with. It shows the total interest and the payoff date for each, so you can see what the behavioural approach actually costs you.

What does the compound interest calculator assume?

It applies a fixed rate over the whole term at the compounding frequency you choose, and adds any regular contribution you set. Real returns vary year to year, so a constant rate is a simplification — it is useful for comparing scenarios and understanding the shape of compounding, not for predicting an actual balance.

Is the retirement calculator reliable?

It is an estimate, and it is honest about that. It projects a balance from your current savings, contributions and an assumed return, and it cannot model market sequence, tax treatment, changes to contributions, or your actual spending in retirement. Use it to test whether a plan is roughly the right shape, not as a forecast.

Does the inflation calculator use real historical data?

It applies a rate you choose across a period you choose, which lets you model any scenario and see how purchasing power erodes. Because you set the rate, it is not tied to one country's published index — the page explains how to use a published average rate if you want a historical figure.

Can I work out my hourly rate from a salary?

Yes. The Salary to Hourly Calculator converts an annual salary to hourly, daily, weekly and monthly equivalents based on the hours and weeks you actually work. It goes the other way too, which is useful for comparing a contract rate against a permanent offer.

Do these calculators handle any currency?

Yes. They are arithmetic tools, so the currency is whatever you are thinking in — the math is identical. Nothing is converted between currencies, and no exchange rate is fetched, which is part of why nothing needs to leave your browser.

Are they free to use?

Yes. Every calculator is free, unlimited, and needs no account. There is no paid tier, no trial, and nothing to install.

Still have questions?

If you can't find the answer you're looking for, feel free to contact our support team.

Contact Us