Kenya T-Bill Calculator (91, 182 and 364 days)
Work out what a Kenyan Treasury bill costs and pays: CBK's 364-day pricing, the 15% withholding tax, and your return after tax, in KES.
Kenya CBK conventions and KES. Not in Kenya? Use the general calculator.
| Face value | KES 100,000.00 |
|---|---|
| Price per 100 | 98.0392 |
| Price | KES 98,039.20 |
| Discount (income before tax) | KES 1,960.80 |
| Tax (15%, paid when buying) | KES 294.12 |
| Same bill as a yield (364 days) | 8.00% |
| Same bill as a discount rate (364 days) | 7.84% |
How the calculator works
A Treasury bill pays no interest. You buy it for less than its face value and get the full face value back at maturity; the difference is the discount, your income. How the price is worked out depends on how the rate is quoted:
- Yield (a return on what you pay): price = face value ÷ (1 + rate × days ÷ days in a year).
- Discount rate (a discount off the face value): price = face value × (1 − rate × days ÷ days in a year).
The same 10% gives a lower price as a discount rate than as a yield, which is why it matters which one your auction notice uses. The results show both, so you can compare a bill with one quoted the other way.
Your return after tax is the income after tax divided by the cash you paid, turned into a yearly rate on a 365-day year. It's the figure to compare with a savings account or a money market fund.
Kenyan T-bills
- The Central Bank of Kenya auctions 91, 182 and 364-day bills every week. Bids close on Thursday and results are published on CBK's website.
- Rates are quoted as a yield on a 364-day year, which is how this page is set up.
- Withholding tax of 15% applies to the discount and is collected when you buy, so you pay the price plus the tax and receive the full face value at maturity.
- The minimum is 100,000 shillings of face value, bought through CBK's DhowCSD or a bank or broker.
Estimates to help you plan, not financial or tax advice. Rates, conventions and tax rules change: check the figures against your own statement, CBK's auction results and KRA.
Frequently asked questions
How is the price of a Kenyan T-bill calculated?
The Central Bank of Kenya quotes T-bill rates as a yield on a 364-day year. Price per 100 = 100 ÷ (1 + rate × days ÷ 364). On 100,000 face value of a 91-day bill at 8%, that is 98,039.20.
How much tax do I pay on a T-bill in Kenya?
Withholding tax of 15% on the discount (the difference between face value and price). Rates can change with each Finance Act, so check KRA for the current rate.
What is the minimum investment in a Kenyan T-bill?
100,000 shillings of face value, through CBK's DhowCSD or a bank or broker.
Why is my return lower than the auction rate?
The auction rate is before tax and on a 364-day year. Your return after the 15% tax, on a 365-day year, is lower: an 8% rate works out at roughly 6.8% after tax.