Business planning
Build a monthly profit projection from explicit business assumptions
A projection is a scenario you can change, not evidence that revenue will arrive. Start with a model small enough to inspect and separate assumptions from measured business results.
Start with one month you can explain
Suppose revenue is 10,000, variable costs are 30% of revenue, and fixed costs are 4,000. Variable costs are 3,000 and operating profit is 3,000. With no growth for twelve months, operating profit totals 36,000. An initial outlay of 5,000 leaves a modeled cumulative surplus of 31,000.
Use one currency throughout. Variable costs in this tool are a single percentage of revenue, and fixed costs stay constant. If costs have tiers, minimum fees, or separate unit drivers, this simplified model may be insufficient. Do not hide those conditions in an unexplained blended percentage.
Compare assumptions instead of trusting one forecast
Make a base case, a lower-demand case, and a higher-cost case. A growth percentage compounds from one month to the next. Ten percent monthly growth is very different from ten percent over the full year. The tool rounds revenue and variable costs half up to cents each month and shows the monthly series for inspection.
The first recovery month means the cumulative modeled surplus reaches zero after the initial outlay. It is not an investment return promise. A later loss can make the balance negative again, so inspect the ending balance and the full sequence.
Separate operating profit from cash timing
This model excludes tax, financing, working-capital timing, depreciation, and inflation. A profitable invoice may remain unpaid, while inventory or loan payments can require cash before the related revenue is collected. Build a separate timing model when those effects matter.
Save scenarios with their assumptions and reporting period. Replace assumptions with measured values as you learn, then compare what changed. The useful output is a decision you can explain, such as the revenue needed to cover fixed costs, rather than a precise-looking prediction.
Authored 2026-10-29. Worked examples checked against the shipped tools; no jurisdiction-specific tax advice is supplied. Examples use the assumptions stated here; authority guidance can change.