Many small business owners in Nigeria celebrate a positive net profit at the end of the month, unaware that one underperforming product is quietly eroding the gains made by their most successful lines.
When operators do not track profit by product instead of the whole business, unprofitable lines can hide behind those that perform exceptionally well. This blind spot often leads to cash flow strain, even as overall sales appear to grow.
The danger of aggregate profit tracking
Aggregate accounting combines all revenues and expenses into a single income statement. While this satisfies tax requirements and general reporting, it fails to reveal which specific products are generating cash and which are consuming it.
Consider a Lagos-based commercial bakery that produces loaves of bread, packaged chin-chin, and custom celebration cakes. The monthly profit and loss statement might show a healthy net margin of 15% across the entire business.
However, a closer look at individual lines might reveal that while bread and chin-chin yield high margins due to fast turnover and automated production, the custom cakes are actually loss-making. The intense manual labor, premium ingredients, and long preparation times for custom cakes consume more resources than their selling price covers.
Without product-level tracking, the owner might decide to run an expensive marketing campaign for the custom cakes, unknowingly accelerating the drain on the business’s cash reserves.
Common mistakes in product costing
SMEs frequently make critical errors when attempting to calculate the profitability of individual items. The most common error is the equal allocation of fixed overheads.
Many business owners divide total monthly rent, administrative salaries, and utility bills equally among their products. If a business has three product lines, they simply allocate 33% of the overheads to each.
This approach distorts reality. If one product takes up 80% of the warehouse space and requires 70% of the machine run-time, it must bear a larger share of those expenses than a product that is packaged and shipped immediately.
Another common mistake is ignoring direct labor costs. Founders often calculate the cost of raw materials but fail to factor in the hourly wages of the staff directly involved in assembling, packaging, or delivering a specific item.
Steps to track profit by product
Shifting from aggregate tracking to product-level profitability requires a systematic approach to cost allocation.
First, isolate the direct costs for each product. These are expenses that disappear entirely if you stop making that specific item, such as raw materials, packaging, and direct manufacturing labor.
Second, establish a logical allocation key for shared indirect costs based on consumption drivers. For example, allocate warehouse rent by the square meters each product occupies, and allocate electricity by machine hours used.
Third, calculate the contribution margin for each product line by subtracting direct costs from revenue. This reveals how much each product contributes toward covering fixed overheads and generating net profit.
Finally, run this analysis monthly. Regular monitoring allows management teams to spot rising input costs early and adjust retail prices before margins collapse entirely.
Improving cash flow and strategy
Once product profitability is clear, founders can make informed strategic decisions rather than relying on intuition.
Low-margin or loss-making products do not always need to be discontinued immediately. In some cases, businesses can renegotiate bulk pricing with suppliers, reduce packaging costs, or increase the selling price to restore profitability.
Alternatively, the business can shift its sales focus and marketing budget toward high-margin products that generate cash quickly, improving overall liquidity and reducing reliance on external working capital.
To begin this transition, review your product list this week and identify your top three revenue-generating items. Calculate the exact direct costs and labor time required for each, and compare these figures against their current retail prices to find their true contribution margins.
