See how your money grows. (Spoiler: compound interest is wild.)
Free calculators for investment, bond, salary, and more
RunYourNumbers is a set of free, South African–focused calculators for the questions you actually ask before making a financial move: what will my take-home pay be, what will this bond really cost me, and what does compound interest do to my savings over ten or twenty years.
Try it: R10,000 growing at 8% a year
R 46 610
after 20 years — up R 36 610 from your original R 10 000
Five calculators, not fifty. Compound interest, bonds, take-home pay, two-pot retirement, and personal loans are the ones people actually reach for before a real decision: signing a bond, changing a pension contribution, deciding whether that loan is worth it.
Local rules, not global averages. SARS tax brackets, UIF, medical aid tax credits, prime-linked bond rates, and the two-pot system that came into effect in September 2024 all behave differently here than in a generic US or UK calculator. We built these against South African rules specifically, not a template with the currency symbol swapped out.
Compound Interest
See how your money grows over time
🏠Bond Repayment
Monthly repayments, total interest, and what your bond really costs
💼Take-Home Salary
What actually lands in your account after tax and deductions
🏺Two-Pot Retirement System
See how your retirement, savings, and vested pots grow under the two-pot rules
💳Personal Loan
Repayment schedule and total cost of borrowing
Every calculator uses local numbers: SARS tax brackets, UIF, medical aid tax credits, prime-linked bond rates. That means the result matches what you'd see on a payslip or a bond quote, not a generic global estimate. Enter your numbers, see the breakdown, and adjust until the picture makes sense.
No login is required to use any calculator. Create a free account only if you want to save your results and come back to them later.
Results are estimates based on your inputs. They don't account for individual fees, taxes, or personal circumstances. Nothing on this site is financial advice, so always speak to a qualified adviser before making financial decisions.
What's next
Calculators and features on the way. No promises on dates, good math takes time.
Debt Payoff
Snowball vs. avalanche — see which clears your debt faster
Export & Share
Download your results as a PDF or share a link to a calculation
Scenario Comparison
Run two sets of numbers side by side to see which wins