OPEX Budget Calculator

Build a board-ready OPEX budget from monthly operating expense lines, add a contingency buffer, and see monthly, annualized, and horizon totals.

OPEX Budget Calculator

Build a clean operating expense (OPEX) budget from monthly line items, add a contingency, and see totals for your chosen horizon—plus optional benchmarks vs revenue and per employee.

How far you want the budget to cover

$

Used only to calculate OPEX as a % of revenue. Leave as 0 if you don’t want this benchmark.

Average number of employees during the budget period (used for OPEX per employee)

%

Small buffer for the unknowns (price increases, one-off costs, timing differences)

$

Fully-loaded payroll for the month (salary, employer taxes, benefits, bonuses if you treat them as OPEX)

$

Office rent, utilities, cleaning, security, coworking fees

$

Recurring SaaS subscriptions, cloud tools, licenses, per-seat software

$

Paid media, events, content, sales tools, sales enablement (exclude COGS)

$

Insurance, professional services, travel, admin, misc. operating expenses

Scenarios
Try a few common profiles to sanity-check your assumptions.
Lean startupGrowing SMBEnterprise team

Results

  • Base monthly OPEX$
  • Contingency (monthly)$
  • Total monthly OPEX$
  • Total budget (horizon)$
  • Annualized OPEX (run-rate)$
  • OPEX as % of revenue— %
  • OPEX per employee (monthly)$

Enter your inputs above to calculate the results.

What is an OPEX budget?

An OPEX budget is a forward plan for the recurring operating expenses needed to run the business, typically SG&A and R&D, excluding capital expenditures (CAPEX).

It matters because OPEX is the biggest lever on operating profit, EBITDA, burn rate, cash runway, hiring pace, and variance analysis against actuals.

Formula

Base monthly OPEX = Payroll + Facilities + Software and tools + Marketing and sales + Other OPEX
Monthly contingency = Base monthly OPEX × Contingency rate
Total monthly OPEX = Base monthly OPEX × (1 + Contingency rate)
Budget for horizon = Total monthly OPEX × Number of months
Annualized OPEX = Total monthly OPEX × 12
OPEX-to-revenue = Annualized OPEX ÷ Annual revenue

Example

Assume a 3-month horizon, 25 employees, and a 5% contingency:

  • Payroll: $150,000 per month
  • Facilities: $8,000 per month
  • Software and tools: $4,000 per month
  • Marketing and sales: $12,000 per month
  • Other OPEX: $3,000 per month
Base monthly OPEX = 150,000 + 8,000 + 4,000 + 12,000 + 3,000 = 177,000
Monthly contingency = 177,000 × 5% = 8,850
Total monthly OPEX = 177,000 + 8,850 = 185,850
Budget for horizon = 185,850 × 3 = 557,550
Annualized OPEX = 185,850 × 12 = 2,230,200
OPEX per employee = 185,850 ÷ 25 = 7,434

Frequently Asked Questions

What should I include in “Payroll (monthly)” for an OPEX budget?

Put the recurring people cost you want to budget as OPEX (salaries + employer taxes + benefits, if you want “fully loaded”). If you only enter base salaries, your OPEX will be understated.

What’s the difference between “Base monthly OPEX” and “Total monthly OPEX”?

Base monthly OPEX is the sum of your monthly categories. Total monthly OPEX adds the contingency buffer on top of that base.

How does “Contingency” work, and when should I use it?

It adds a risk buffer to cover unknowns (price increases, hiring timing, vendor creep). If your plan is stable, keep it low; if your plan is volatile, increase it.

What does the “Annual revenue (optional)” field change?

It lets the calculator compute an OPEX-to-revenue ratio so you can sanity-check burn versus revenue scale (useful for benchmarking and board-style reporting).

Sources & Methodology