Size the shortfall and the top-up to close it.
Monthly income gap
—
Extra pot needed
—
Extra monthly contribution
—
From a monthly shortfall to a pot you can size
Plenty of Kenyans know roughly what they want to live on in retirement and have a vague sense their pension will not cover it, but the gap stays abstract until you put a number on it. This calculator turns the worry into three concrete figures. It starts with the gap between the income you want and the income you expect, converts that monthly shortfall into the lump sum you would need to generate it, and then works backwards to the amount you must save each month to build that lump sum by the time you stop working.
The chain is simple once you see it. A monthly gap becomes an annual gap when you multiply by twelve. The annual gap becomes a required pot when you divide by a safe withdrawal rate. The required pot becomes a monthly saving when you spread it over the years you have left, allowing for investment growth along the way. Each link is just arithmetic, but doing it in your head is hard, which is what the tool is for.
Two assumptions you choose, and why they matter most
Unlike the tax tools on this site, the key numbers here are not set by the Kenya Revenue Authority or any statute. They are planning assumptions you pick, and the answer is extremely sensitive to them. The first is the safe withdrawal rate, defaulting to 4 percent. That is a widely cited rule of thumb for how much of a pot you can draw each year without exhausting it, not a Kenyan legal figure, and it is debated. The second is the expected return on your savings, defaulting to 8 percent. Treat both as dials, not facts. Nudging the withdrawal rate from 4 to 5 percent shrinks the pot you need by a fifth, and a higher assumed return slashes the monthly saving because compounding does more of the work. Run the tool two or three times with cautious and optimistic settings to see the range you are really planning within.
Closing a KES 60,000 monthly gap over 20 years
Take someone targeting KES 150,000 a month in retirement who projects only KES 90,000 from their existing pension and NSSF. They have 20 years to go, assume a 4 percent withdrawal rate, and expect 8 percent annual growth on what they save. Here is how the tool builds the answer.
| Step | Working | KES |
|---|
So the KES 60,000 monthly gap implies a KES 18 million pot, reachable with about KES 30,559 saved every month for 20 years. The chart shows how growth carries most of the load: only a fraction of that final pot is money you put in.
The silent enemy the tool does not show: inflation
Here is the edge case worth understanding. The calculator works in today's shillings. A KES 150,000 target that feels comfortable now will buy far less in 20 years, because prices keep climbing. If you want KES 150,000 of today's spending power at retirement, the nominal target you should actually plug in is higher, and you should revisit it every few years. The tool does not inflate the target for you, deliberately, so that you stay in charge of the assumption. The practical move is to express your target in today's money, then bump the figure up periodically as your salary and the cost of living rise, rerunning the gap each time.
A second judgement: the monthly saving is not fixed for life. Most people's incomes rise over a career, so a saving that looks heavy at 30 becomes easy at 45. If today's required figure feels out of reach, start with what you can manage and increase it whenever your pay does. The cost of delay is steep, though, because compounding rewards the years you cannot get back, so even a modest amount started now beats a larger amount started in five years. Use this as a direction-setter, then refine it with a licensed financial adviser who can factor in your tax position and the specific funds available to you.
What does "safe withdrawal rate" actually mean here?
It is the share of your pot you draw in the first year of retirement, set so the pot has a strong chance of lasting your lifetime rather than running dry early. The tool defaults to 4 percent, the most quoted rule of thumb, which implies a pot 25 times your annual need. It is a planning convention, not a guarantee or a Kenyan legal rate, and a more cautious retiree might use 3.5 percent while a more aggressive one uses 5 percent. Lowering the rate raises the pot you must build.
Does the projected income include NSSF and my employer pension?
It should. The projected monthly income field is whatever you expect to receive from every source combined, your NSSF, any occupational or personal pension, rental income, and so on. The tool does not estimate those for you; you enter your own best projection. If you are unsure what your NSSF and pension will pay, use the retirement savings projector first, then bring that figure here as your projected income.