How much working capital does a small business need?
Most small businesses need three to six months of operating expense in accessible working capital. Inventory-heavy and project-based businesses need the top of that range because cash leaves before it arrives; subscription and prepaid businesses can safely run on two to three months.
Working capital targets by business model
| Business model | Months of opex | Why |
|---|---|---|
| Subscription / prepaid | 2–3 months | Cash arrives before delivery |
| Professional services | 3–4 months | 30–60 day receivables |
| Retail / ecommerce | 4–6 months | Inventory ties up cash |
| Construction / projects | 5–7 months | Progress billing lag |
| New franchise or startup unit | 4–6 months | Ramp before break-even |
How to read this table
- Construction / projects sits at the top of the table (5–7 months) — progress billing lag. If your situation looks like this row, plan against the upper half of the range rather than the midpoint.
- Subscription / prepaid anchors the bottom (2–3 months) — cash arrives before delivery. Treat this as the conservative case you should still be profitable at.
- The gap between the top and bottom row is roughly 3.5×. That spread is why a single blended average is close to useless here — pick the row that matches your setup instead of averaging the column.
- Most rows are ranges, not single figures. The low end usually reflects a weaker month, a softer audience geography, or an unoptimised setup; the high end reflects a well-run, well-targeted operation of the same size.
- With 5 reference points in the "working capital targets by business model" table, the fastest way to use this page is to find the closest row, take its months of opex, then stress-test it ±30% before you build a plan on it.
Context
Profitable businesses fail on timing, not on margin. The cash conversion cycle — days of inventory plus days of receivables minus days of payables — tells you how long your money is out of the building, and the working capital requirement is simply that cycle multiplied by daily operating cost. Shortening the cycle is cheaper than financing it: deposits up front, shorter payment terms, and faster invoicing each release cash permanently, while a line of credit rents it monthly.
What moves this number
Owner compensation treatment
Whether the owner's pay sits above or below the profit line changes reported margin by 10–20 points on identical economics. Normalise to seller's discretionary earnings before comparing anything.
Fixed cost base
Rent, insurance and salaried staff set the break-even point. A business with a low fixed base survives a soft quarter that would close a heavily-loaded competitor.
Customer concentration
When the top client exceeds a quarter of revenue, both cash flow and sale value are discounted. Diversification is worth real margin.
Cash conversion cycle
Days of inventory plus receivables minus payables decides how much working capital the business needs to fund the same revenue.
Methodology
Cash conversion cycle modelling across common business models, using median receivable, payable and inventory days per sector applied to monthly operating expense.
Assumptions and caveats
- Figures are pre-tax and assume the owner is paid a market-rate salary unless a row says otherwise.
- Sector benchmarks hide wide local variation in rent, wages and demand.
- This page was last reviewed on 2026-08-12. Ranges are updated as new data lands, so re-check before using them in a contract or a plan.
- Use these numbers as a starting range, not a guarantee — your own historical data always beats a benchmark.
Frequently asked questions
How much working capital does a small business need?
Most small businesses need three to six months of operating expense in accessible working capital. Inventory-heavy and project-based businesses need the top of that range because cash leaves before it arrives; subscription and prepaid businesses can safely run on two to three months.
Which option pays the most in the working capital targets by business model table?
Construction / projects, at 5–7 months (Progress billing lag). That row represents the strongest case in this dataset, so use it as an upper bound rather than an expectation.
What is a realistic low-end figure?
Subscription / prepaid at 2–3 months (Cash arrives before delivery). Plan your costs so the low end still works, then treat anything above it as upside.
Why do the numbers vary so much?
The spread between the highest and lowest row is about 3.5×. Owner compensation treatment and fixed cost base explain most of that gap — see the drivers section above for the full list.
Where do these numbers come from?
Cash conversion cycle modelling across common business models, using median receivable, payable and inventory days per sector applied to monthly operating expense.
How can I estimate my own number instead of using a benchmark?
Use the Cash Flow Calculator on RevenueLab — it takes your own inputs and returns a figure specific to your setup, which is always more accurate than a published range.
Model your own numbers
More answers in this category
- How much profit does a small business make?
- What multiple do small businesses sell for?
- How much does a laundromat make per month?
- How much does a vending machine make per month?
Last updated 2026-08-12.