Why does a small rate difference matter so much?

Because of compound growth. Over 20 years, KES 1,000,000 at 9% grows to KES 5.6M; at 13% it grows to KES 11.5M. That’s more than double from a 4-percentage-point difference. The gap widens with every additional year. See the math in the Compound Interest Calculator.

Is it safe to compare options at their "typical" rates?

Typical rates are realistic ranges based on 2026 Kenya market data. They are not guarantees — actual yields vary daily, and past performance does not predict future results. Use this comparison as a directional tool, then verify current rates for any specific product on the Serrari Marketplace.

Should I pick the highest rate every time?

Not necessarily. Higher rates often mean lower liquidity (T-Bills lock your money for 91+ days) or higher risk (unit trusts have variable returns). If you might need the money in 30 days, a bank savings or MMF is safer despite the lower yield. Match the vehicle to your time horizon and risk tolerance.

How do I use this calculator for a real decision?

Enter your actual starting amount and monthly contribution. Set the investment period to match your goal (e.g. 3 years for a car, 10 years for a house). Look at the final value AND consider liquidity and risk. Use the comparison to inform where to park your money — then verify live rates on the Serrari Marketplace before investing.

Compare Investments Calculator Kenya — Side-by-Side

Q: How is tax treatment different across these options?

Treasury Bills: 15% WHT, deducted at source. T-Bonds: 15% WHT (10 years or less) or 10% (longer). MMFs, unit trusts, bank savings, SACCOs: 15% WHT on interest income. Infrastructure bonds: fully tax-exempt. After-tax returns narrow the gap between products — the calculator above shows gross returns, so factor in your personal tax situation for the fairest comparison. Use the Tax on Returns Calculator to see your net figures.

Enter your starting amount, monthly contribution, and investment period. We’ll compare how your money grows across Bank Savings, MMFs, T-Bills, SACCOs and more — side-by-side.

Updated April 2026

Comparing investment options side-by-side reveals how dramatically small rate differences compound over time. For a KES 100,000 lump sum + KES 5,000/month over 5 years, money growing at 3.5% ends near KES 446,000 — while at 10% it grows to about KES 552,000. That KES 105,000 gap is the power of choosing the right vehicle. The calculator below starts with today's money market fund and 364-day T-bill rates from Serrari's live rate pages; edit any rate to compare your own options.

Calculator 11

Compare Investments: Side-by-Side

See how the same money grows across different Kenya investment options.

Starting amount

KES

Monthly contribution

KES

Investment period (years)

Annual interest rates

Bank Savings

MMF average

Top MMF

364-day T-Bill

SACCO

Best option (highest final value)

SACCO — KES 610,358

1. SACCOKES 610,358 (13%)

2. Top MMFKES 570,673 (11.01%)

3. MMF averageKES 536,347 (9.15%)

4. 364-day T-BillKES 534,396 (9.04%)

5. Bank SavingsKES 446,425 (3.5%)

Option	Rate	Final	Gain
SACCO	13%	KES 610,358	KES 210,358
Top MMF	11.01%	KES 570,673	KES 170,673
MMF average	9.15%	KES 536,347	KES 136,347
364-day T-Bill	9.04%	KES 534,396	KES 134,396
Bank Savings	3.5%	KES 446,425	KES 46,425

In plain English

Starting with KES 100,000 plus KES 5,000/month over 5 years: SACCO wins at KES 610,358 — that's KES 163,933 more than Bank Savings. Higher rates beat lower rates dramatically over time thanks to compound growth.

How the Investment Comparison Formula Works

FV = P(1 + r/n)ⁿᵗ + PMT × [(1 + r/n)ⁿᵗ − 1] / (r/n)

Future Value

Principal

PMT

Monthly Cont.

Annual Rate

Periods/Year

This formula combines two components: the growth of your initial lump sum and the growth of every monthly contribution. The first part calculates how your principal compounds over time. The second part calculates the future value of a series of equal monthly deposits, each compounding from the moment it is contributed. Together, they give you the total amount you will have at the end of the investment period.

By running this formula at different interest rates, you can see exactly how much more you earn with higher-yielding products. The gap widens dramatically over longer periods — which is why compound interest favours patient investors. For a single lump-sum projection, try the Future Value Calculator. To see how fast your money doubles at any rate, use the Rule of 72 Calculator.

Kenya Investment Vehicles Compared (2026)

Typical rates, risk levels, and liquidity for each option in the calculator.

Product	Rate	Risk Level	Liquidity	Min. Investment
Bank Savings	3 – 5%	Very low	Instant	KES 0
Money Market Funds	Today's yields →	Low	Next-day	KES 100
Treasury Bills	Latest auction →	Very low	91–364 days	KES 50,000
SACCO Savings	8 – 14%	Medium	Varies	Varies
Treasury Bonds	Today's yields →	Very low	2–25 years	KES 50,000
Unit Trusts (Balanced)	Today's yields →	Medium	3–5 days	KES 1,000

Compare Live Rates on Marketplace →

Side-by-Side Growth: Sample Scenarios

How the same money grows across different rates and time horizons.

Starting + Monthly	Rate	Years	Final Value
KES 100K + 5K/mo	3.5%	5	KES 446,425
KES 100K + 5K/mo	9.4%	5	KES 540,813
KES 100K + 5K/mo	16%	5	KES 676,558
KES 500K + 10K/mo	9.4%	10	KES 3,254,829
KES 500K + 10K/mo	13%	10	KES 4,262,236
KES 1M + 20K/mo	11.5%	20	KES 28,367,573

Need to project a single lump sum? Try the Future Value Calculator.

Compare Investments Calculator — FAQ

Treasury Bills pay the rate set at each weekly CBK auction (see the latest T-Bill rates), less 15% withholding tax. However, they lock up your money for 91–364 days and require a KES 50,000 minimum. For flexibility, top money market funds are usually the best-paying liquid option; their yields are updated daily. Always weigh rate against liquidity and risk.

Treasury Bills: 15% WHT, deducted at source. T-Bonds: 15% WHT (10 years or less) or 10% (longer). MMFs, unit trusts, bank savings, SACCOs: 15% WHT on interest income. Infrastructure bonds: fully tax-exempt. After-tax returns narrow the gap between products — the calculator above shows gross returns, so factor in your personal tax situation for the fairest comparison. Use the Tax on Returns Calculator to see your net figures.

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T-Bill Returns

Net-of-tax Treasury Bill yield

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Net FD interest after 15% tax

Serrari Marketplace

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Serrari Markets provides independent financial data and educational tools. Serrari Limited is a financial data, education and investment-origination platform. Serrari is not a fund manager, investment bank or deposit-taking institution and does not hold client investment funds. Where clients elect to invest, transactions are executed through appropriately licensed and regulated third-party financial institutions. The relevant product provider remains responsible for the issuance, management and custody of each investment. Calculator results are estimates for educational purposes. Always consult a licensed advisor before making investment decisions.

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