| Office rent |
Fixed |
Include $3,000 per month as recurring overhead from Month 1 through Month 60. |
Leaving rent out because early staff can work remotely. |
| Utilities and internet |
Fixed |
Include $500 per month as base operating overhead across the forecast period. |
Treating small bills as immaterial and understating break-even revenue. |
| Legal and accounting retainers |
Fixed |
Include $1,500 per month as recurring administrative overhead, not launch spend. |
Counting retainers as one-time setup work instead of monthly coverage. |
| Year 1 payroll |
Fixed |
Include about $30,000 per month: founder, engineering, sales, and marketing staffing at planned first-year FTE levels. |
Using annual salaries but forgetting to convert them into monthly break-even load. |
| Planned marketing budget |
Semi-fixed |
Model the first-year budget at $150,000 per year, or $12,500 per month, unless management changes the plan. |
Mixing planned campaign budget with CAC and double-counting acquisition spend. |
| Cloud hosting and data storage |
Variable |
Apply 4.0% of revenue in the first year, declining to 3.0% by the mature year. |
Booking usage fees as fixed when customer activity drives the bill. |
| Third-party API licenses |
Variable |
Apply 3.0% of revenue in the first year, declining to 2.0% by the mature year. |
Ignoring data access fees until gross margin looks too high. |
| Customer support load |
Semi-variable |
Start support capacity in Month 13, then scale coverage as the active customer base rises. |
Assuming support stays flat after paid users increase. |