Why per-plate cost matters
A menu price set once and left alone slowly stops paying for itself. Vegetable prices in Nairobi move with the seasons and the rains, sometimes week to week, and a dish that made money in one month can lose it in the next without anyone noticing. Knowing what each plate costs is how you notice.
Step 1: write a recipe card for each dish
For each dish, write down every ingredient and how much one batch uses, and how many portions the batch makes. Use the unit you buy in: kilos for tomatoes and onions, bunches for sukuma and dhania, pieces for pineapple and cabbage. If your cooks work by eye, weigh one batch while they make it.
Step 2: price the usable kilo, not the bought kilo
Most costing mistakes happen here. You pay for the whole kilo, but you only cook what is left after peeling, trimming and sorting.
Cost per usable kilo = price per kilo ÷ usable share
For example, if onions are KSh 165 a kilo and your kitchen loses 10% in peeling, the usable share is 90% and each usable kilo costs KSh 165 ÷ 0.9, about KSh 183. Weigh your own produce before and after prep a few times to find your real figures; they depend on your cuts, your staff and the quality you buy. That last point is why the cost of a market run is often higher than it looks.
For bunches and pieces, the units guide explains how to compare and convert.
Step 3: cost the plate
Here are three Kenyan staples costed with Wapishi's prices for the week of 10 November 2026. The quantities are example recipes for 10 portions, before trimming, and leave out oil, salt and spices. Use your own recipe cards and the current price list for your real numbers.
Kachumbari, 10 portions
| Ingredient | Amount | Price | Cost |
|---|---|---|---|
| Tomatoes | 1 kg | KSh 90 per kg | KSh 90 |
| Red onions | 0.5 kg | KSh 165 per kg | KSh 83 |
| Dhania | 1 bunch | KSh 30 per bunch | KSh 30 |
| Green chilli | 50 g | KSh 130 per kg | KSh 7 |
| Lemon | 200 g | KSh 110 per kg | KSh 22 |
| Total | KSh 231, about KSh 23 a portion |
Sukuma wiki, 10 portions
| Ingredient | Amount | Price | Cost |
|---|---|---|---|
| Sukuma | 5 bunches | KSh 35 per bunch | KSh 175 |
| Onions | 300 g | KSh 165 per kg | KSh 50 |
| Tomatoes | 500 g | KSh 90 per kg | KSh 45 |
| Total | KSh 270, about KSh 27 a portion |
Breakfast fruit plate, 10 plates
| Ingredient | Amount | Price | Cost |
|---|---|---|---|
| Pineapple | 1 piece | KSh 110 per piece | KSh 110 |
| Watermelon | 2 kg | KSh 60 per kg | KSh 120 |
| Pawpaw | 1 kg | KSh 130 per kg | KSh 130 |
| Bananas | 5 pieces | KSh 60 per 5 pieces | KSh 60 |
| Total | KSh 420, about KSh 42 a plate |
Step 4: compare with the menu price
Divide the plate cost by the menu price to get the food cost percentage for that dish. Add the other ingredients on the plate first, such as the ugali, meat or oil, so you are comparing the whole plate with what the customer pays. Set a target for each dish and watch for the ones that drift above it.
Step 5: re-cost when prices move
A single price can move a whole dish. In the kachumbari above, if tomatoes went from KSh 90 to KSh 120 a kilo, the batch would go from KSh 231 to KSh 261, about 13% more, with nothing else changed. When a staple jumps, you can raise the price, adjust the portion, or switch to a dish built on produce that is in season.
- Check prices weekly for your ten most-used items. Wapishi's price list shows each week's prices and what changed.
- Re-cost your best sellers first. They carry the most money.
- Count waste as a cost. Produce that spoils before it is used raises the real cost of every plate. The food waste guide shows where it usually goes.
Where costing usually goes wrong
| Mistake | Fix |
|---|---|
| Costing the bought kilo | Cost the usable kilo, after peeling and trimming. |
| Bunches that change size | Weigh a few bunches, or buy from a supplier whose bunches are consistent. |
| Last month's prices | Re-cost from this week's prices. |
| Ignoring spoilage | Track what is thrown away and add it to the cost. |
| Cheap produce with a low usable share | Compare suppliers on cost per usable kilo, not the price per kilo. |
Costing with Wapishi
Wapishi publishes its prices every week on the price list and shows live prices in the online shop, so you can cost a menu before you order. Every order comes with an eTIMS invoice, which makes it easier to match what you spent with what you sold. Qualified partners can pay on 30-day accounts, and you can try us first with a free sample pack on WhatsApp: 0769 912 227.