A practical hub of 18 accurate financial calculators — from budgeting and PAYE tax to loans, mortgages, investing, ROI, IRR and cash flow. Type a number and see the answer instantly, with the formula and assumptions shown for every tool.
No calculator matches that search. Try “loan”, “tax”, “investment” or “NPV”.
01
Personal finance
Day-to-day money planning: see where your income goes, how fast a goal is reached, what you'll have at retirement, what tax you owe, and how inflation erodes value over time.
Budget calculator
Balance monthly income against your spending and see what's left to save.
KSh
KSh
KSh
KSh
KSh
KSh
KSh
KSh
Money left over—
Total spending—
Savings rate—
Formula & notes
Money left = income − all spending. Savings rate = savings ÷ income. A common guideline is the 50/30/20 split (needs / wants / savings). A negative "money left over" means you're spending more than you earn.
Savings goal calculator
Find the monthly deposit needed to hit a target by a set date.
KSh
KSh
yrs
% p.a.
Save each month—
Total you'll deposit—
Interest earned—
Formula & notes
Deposits are assumed at each month-end with monthly compounding. Required deposit solves FV = current·(1+r)^n + D·((1+r)^n−1)/r for D, where r is the monthly rate and n the number of months. If your current savings already grow past the goal, the required deposit is zero.
Retirement calculator
Project your nest egg and the income it could support.
KSh
KSh
% p.a.
Balance at retirement—
Total you'll contribute—
Est. income / month (4% rule)—
Formula & notes
Future value grows current savings plus month-end contributions at a constant monthly return. Retirement income uses the 4% safe-withdrawal rule (annual income ≈ balance × 4%), shown per month. Figures are nominal — not adjusted for inflation. Use the inflation tool to see real buying power.
Tax calculator · Kenya PAYE
Estimate PAYE income tax and take-home pay using KRA graduated bands.
KSh
KSh
PAYE per month—
PAYE per year—
Effective tax rate—
Net pay after PAYE / month—
Formula & assumptions
Graduated monthly bands (Finance Act 2023): 10% on the first KSh 24,000, 25% to 32,333, 30% to 500,000, 32.5% to 800,000, 35% above; personal relief KSh 2,400/month. Taxable income = gross − pre-tax deductions. This estimates income tax only — it excludes SHIF (2.75%), NSSF and the Housing Levy (1.5%) unless entered as deductions. Verify current rates with KRA.
Inflation & future value calculator
See how prices rise and what today's money will be worth later.
KSh
%
yrs
Same buying power will cost—
Today's amount will be worth—
Formula & notes
Future cost of the same basket = amount·(1+i)^years. Real (buying-power) value of today's money later = amount ÷ (1+i)^years. Assumes a constant annual inflation rate compounded yearly.
02
Debt & borrowing
Work out repayments and interest before you sign. Every tool here fully amortises the balance at a fixed rate with monthly payments unless noted.
Loan calculator
Monthly payment and total interest on any fixed-rate loan.
KSh
% p.a.
yrs
Monthly payment—
Total repaid—
Total interest—
Formula & notes
Payment = P·r / (1 − (1+r)^−n), where P is the amount, r the monthly rate (APR ÷ 12) and n the number of months. Assumes a fixed rate, monthly compounding and full amortisation.
Mortgage calculator
Home-loan payment including optional taxes and insurance.
KSh
KSh
% p.a.
yrs
KSh
KSh
Monthly payment (all-in)—
Principal & interest—
Loan amount—
Total interest over term—
Formula & notes
Loan = price − down payment. Principal & interest use the standard amortising payment formula; taxes and insurance are spread evenly across 12 months and added on top. Assumes a fixed rate for the full term.
Auto loan calculator
Car finance payment after down payment and trade-in.
KSh
KSh
KSh
% p.a.
mo
Monthly payment—
Amount financed—
Total interest—
Formula & notes
Amount financed = price − down payment − trade-in. Payment uses the same amortising formula as the loan tool over the number of months you enter. Excludes registration, insurance and taxes.
Credit card payoff calculator
How long a fixed payment takes to clear a card, and the interest cost.
KSh
% p.a.
KSh
Time to pay off—
Total paid—
Total interest—
Formula & notes
Months = −ln(1 − B·r/M) / ln(1+r), where B is the balance, r the monthly rate and M the payment. If your payment doesn't exceed the first month's interest (B·r), the balance never clears — the tool flags this.
Debt consolidation calculator
Compare several debts against one consolidated loan.
Your current debts (balance · APR% · monthly payment)
%
mo
New monthly payment—
Current total monthly—
Monthly difference—
New total interest—
Formula & notes
Balances are summed and refinanced as one amortising loan at the new APR and term. Current payments are assumed fixed each month. A lower monthly payment over a longer term can still cost more interest overall, so compare both figures.
03
Investment planning
Grow and evaluate money over time. These tools cover projected growth, the drag of fees, and the core appraisal metrics — ROI, IRR and NPV — used to judge whether a return is worth it.
Investment calculator
Project your balance and see exactly what fund-manager fees cost you.
KSh
KSh
yrs
% p.a.
% p.a.
Amount to expect (net of fees)—
Keep 100%Fees take 0%
Value before fees—
Cost of investing (fees)—
Total you invest—
Formula & assumptions
Net rate = gross − fee. The nominal rate is converted to an effective annual rate, then to a per-contribution-period rate, so mismatched compounding and contribution frequencies stay correct. Contributions are end-of-period. Cost of investing = final value at the gross rate − final value at the net rate.
Compound interest calculator
Grow a lump sum, with optional monthly top-ups, at any compounding frequency.
KSh
KSh
%
yrs
Future value—
Total contributed—
Interest earned—
Formula & notes
Lump sum grows as P·(1+r/n)^(n·t). Monthly top-ups are added at month-end and compounded at the same effective annual rate. "Interest earned" is future value minus everything you put in.
ROI calculator
Total and annualised return on an investment.
KSh
KSh
yrs
Total ROI—
Net profit—
Annualised (CAGR)—
Formula & notes
ROI = (final − invested) ÷ invested. Annualised return is the compound annual growth rate (final ÷ invested)^(1/years) − 1, which spreads the gain evenly across the holding period.
IRR calculator
The rate of return that sets a project's net present value to zero.
KSh
IRR per period—
Periods entered—
Formula & notes
IRR is the rate r solving Σ CFₜ ÷ (1+r)ᵗ = 0, found numerically. Periods are assumed equally spaced — if each cash flow is one year apart, the IRR is annual. Enter the initial outlay as a positive number; it's treated as money out at year 0.
NPV calculator
Today's value of a project's future cash flows at your discount rate.
%
KSh
Net present value—
Verdict—
Formula & notes
NPV = −initial + Σ CFₜ ÷ (1+r)ᵗ for t = 1…n. Each future cash flow is assumed to arrive at period-end. A positive NPV means the project beats your discount rate and adds value.
Annuity calculator
Present or future value of a stream of equal payments.
KSh
%
Value—
Total payments—
Formula & notes
Future value = PMT·((1+r)ⁿ−1)/r; present value = PMT·(1−(1+r)⁻ⁿ)/r. "Start of period" (annuity-due) multiplies the result by (1+r). Use a per-period rate — e.g. divide an annual rate by 12 for monthly payments.
04
Housing decisions
Weigh the big property choices. The mortgage calculator lives in Debt & borrowing — jump to it below — and the rent-vs-buy tool compares the full cost of each path over the years you'll stay.
Mortgage calculator
Already available above — one shared implementation, no duplication. It covers payment, taxes, insurance and total interest.
Compare the total cost of renting against buying over your stay.
KSh
yrs
KSh
KSh
%
yrs
%/yr
%/yr
%
%
Cheaper option—
Net cost to buy—
Net cost to rent—
You save—
Formula & assumptions
Buying cost = down payment + mortgage payments over your stay + upkeep/tax − sale proceeds (home value grown at the appreciation rate, minus remaining loan balance and selling costs). Renting cost = rent totalled with annual rent growth. This is a simplified comparison and ignores tax deductions, transaction taxes on purchase, and investment of the down-payment difference.
05
Business & cash flow
Appraisal and liquidity for businesses. Tax, ROI, IRR and NPV are shared with the sections above — jump straight to them — while the cash flow tool gives a quick period snapshot.
Tax calculator
Estimate income tax with the shared Kenya PAYE tool in Personal finance.
Net cash flow = cash in − cash out. Closing balance = opening balance + net cash flow. Cash-flow margin = net cash flow ÷ cash in. This is a single-period snapshot; for multi-period forecasts, run one period at a time.
06
Frequently asked questions
Quick answers about how these calculators work, what they assume, and how to read the results.
Are these financial calculators free to use?
Yes — every tool runs in your browser at no cost, with no sign-up. Your inputs stay on your device and aren't sent anywhere.
What currency do the calculators use?
Money is shown in Kenyan Shillings (KES / KSh). The underlying formulas are currency-neutral, so the results hold for any currency if you read the figures as your own.
How is the investment calculator's "cost of investing" worked out?
It's the final value at the gross rate minus the final value at the net rate (gross minus the fund manager's fee) — the shillings the fee quietly removes from your return over the whole period.
How accurate is the Kenya PAYE tax calculator?
It uses the graduated PAYE bands from the Finance Act 2023 (10% to 35%) and the KSh 2,400/month personal relief. It estimates income tax only and excludes SHIF, NSSF and the Housing Levy unless you enter them as pre-tax deductions. Always confirm current rates with KRA.
What's the difference between ROI and IRR?
ROI measures total gain relative to what you put in and ignores time. IRR is the annualised rate that makes the present value of every cash flow equal zero, so it accounts for when money comes in and out.
What discount rate should I use for NPV?
Use your required rate of return or cost of capital — the annual return you could earn elsewhere at similar risk. A positive NPV means the project beats that benchmark and adds value.
General information only. These calculators provide estimates using standard formulas and the assumptions noted under each tool. They are not financial, tax, or legal advice. Confirm figures — especially tax rates and loan terms — with a qualified professional or the relevant authority before deciding.