Tax on a 13th cheque or festive bonus.
Net 13th cheque
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PAYE on the cheque
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Gross to net this amount
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Your breakdown
Updates live as you type| Step | Amount (KES) |
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Why a December bonus stings more than your salary
A 13th cheque feels like free money until the payslip lands. The shilling you earn in the bonus is not taxed at some gentle festive rate. It sits on top of everything you have already earned that month, so it is taxed at your marginal rate, the rate on your last and highest band of income. For most salaried Kenyans on a decent wage that top band is 30 percent, and for high earners the calculator can reach into the 32.5 and 35 percent bands. That is why a bonus that looks generous on paper shrinks so much by the time it reaches your M-Pesa.
This tool is built for two people: the employee who wants to know what a promised bonus will actually be worth in hand, and the HR or finance person who has been told to pay someone a clean round net figure and needs to work out the gross. It uses the monthly PAYE bands the calculator applies, with the first KES 24,000 at 10 percent, the slice up to KES 32,333 at 25 percent, income up to KES 500,000 at 30 percent, then 32.5 percent and 35 percent above that. These are the bands as modelled here, and because Kenya revises them through successive Finance Acts you should confirm the current scale on the KRA website before you rely on a figure for payroll.
The arithmetic of stacking a bonus on salary
The calculator does not tax the bonus in isolation. It works out the PAYE on your salary alone, then the PAYE on salary plus bonus, and the difference is the tax the bonus drags in. That difference method is exactly how a real payroll run treats a one-off payment, and it is why the bonus can cross a band boundary even when your normal salary does not.
Take the tool's default: a monthly taxable salary of KES 90,000 and a 13th cheque of KES 90,000. On its own the salary attracts about KES 21,783 of PAYE before personal relief. Add the bonus and the combined KES 180,000 attracts roughly KES 48,783. The bonus has therefore cost you KES 27,000 in extra tax, every shilling of it at the 30 percent band, leaving a net of KES 63,000. Notice the rate: 27,000 on 90,000 is a flat 30 percent, because both the salary and the bonus already sit inside the third band.
That last row is the gross-up, and it surprises people. To put KES 90,000 net in someone's hands when they are already in the 30 percent band, the employer cannot just pay KES 90,000. It has to pay about KES 128,570 gross, because the extra slice climbs through the 30 and then the 32.5 percent band as the cheque gets bigger. The tool solves this by searching for the gross figure whose after-tax value lands on your target.
A practical tip on timing
If your employer is flexible, ask whether a large bonus can be split across two pay periods, for example part in December and part in January. Splitting does not change your annual income, but it can keep each month's combined pay from punching into a higher band, which matters most if a single big cheque would tip you over the KES 500,000 or KES 800,000 monthly thresholds. For people comfortably inside the 30 percent band, as in the example above, splitting saves nothing, because the marginal rate is the same in both months.
Does the bonus affect SHIF, NSSF or the Housing Levy?
This tool isolates PAYE only, but a bonus is gross pay, so in a full payroll run it also feeds the 1.5 percent Affordable Housing Levy and the 2.75 percent SHIF deduction, both modelled elsewhere on this site as employee charges with no cap. NSSF is tiered and usually already maxed out at higher salaries, so a bonus rarely adds to it. Treat the net figure here as the PAYE-only picture and layer the other statutory deductions on top if you need the true take-home.
Is a gratuity or service pay taxed the same way?
Not always. A genuine 13th cheque or festive bonus is ordinary employment income and is taxed exactly as this calculator shows. A retirement gratuity can qualify for a separate tax-free allowance, which the calculator the figures here reflect does not apply, so do not use this page for terminal dues. For anything labelled gratuity, service pay or a retirement lump sum, check the KRA guidance, because the exemptions and the rules around them have shifted with recent Finance Acts.