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💰 Financial · Rex's Toolbox

Business Interruption Insurance Calculator

Size the coverage limit you need to survive a shutdown until you reopen.

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Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.

Try a scenario

Click to load — tweak from there.

Inputs

Result

Recommended BI coverage limit

$337,500

Base need (no buffer)

$258,000

Total monthly loss exposure

$43,000

Daily loss exposure

$1,414

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How to use this

  1. 1Enter average monthly net income ($).
  2. 2Enter monthly continuing fixed expenses ($).
  3. 3Enter expected restoration period (months).
  4. 4Enter contingency buffer (%).
  5. 5Enter extra expense (temp location, rush costs) ($).
  6. 6Read your recommended bi coverage limit on the right — it updates as you type.
  7. 7Hit Share to keep the scenario or send it to someone.

About this calculator

Business interruption (BI) insurance replaces lost net income and covers continuing fixed expenses while your business can't operate after a covered loss like a fire or major equipment failure. Sizing it wrong is one of the most common and costly mistakes — insureds routinely underestimate the restoration period, leaving them exposed after the money runs out. This calculator takes your monthly net income, monthly fixed operating expenses that continue regardless of revenue (rent, loan payments, key salaries), and an expected number of months to restore operations including permitting and rebuild time, then adds a contingency buffer since most restoration timelines run long.

FormulaCoverage need = (monthly net income + monthly continuing fixed expenses) × restoration months × (1 + contingency %).

Worked example

Using the values the calculator loads with:

Inputs

  • Average monthly net income: 25000 $
  • Monthly continuing fixed expenses: 18000 $
  • Expected restoration period: 6 months
  • Contingency buffer: 25 %
  • Extra expense (temp location, rush costs): 15000 $

Results

  • Recommended BI coverage limit: $337,500
  • Base need (no buffer): $258,000
  • Total monthly loss exposure: $43,000
  • Daily loss exposure: $1,414

What each field means

Inputs

Average monthly net income ($)
The average monthly net income used in the calculation, measured in $. Starts at 25000 $ so you have a working example on load.
Monthly continuing fixed expenses ($)
The monthly continuing fixed expenses used in the calculation, measured in $. Starts at 18000 $ so you have a working example on load.
Expected restoration period (months)
The expected restoration period used in the calculation, measured in months. Starts at 6 months so you have a working example on load. Accepted range: 1–36 months.
Contingency buffer (%)
The contingency buffer used in the calculation, measured in %. Starts at 25 % so you have a working example on load. Accepted range: 0–100 %.
Extra expense (temp location, rush costs) ($)
The extra expense (temp location, rush costs) used in the calculation, measured in $. Starts at 15000 $ so you have a working example on load.

Results

Recommended BI coverage limit
Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Base need (no buffer)
Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Total monthly loss exposure
Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Daily loss exposure
Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.

FAQ

What counts as 'continuing fixed expenses'?

Rent or mortgage payments, loan payments, insurance premiums, and salaries for key employees you must retain to reopen — anything that keeps coming due whether or not you're generating revenue. Variable costs tied directly to sales, like materials and hourly staff you'd lay off, typically don't belong in this bucket since they'd naturally drop during a shutdown.

Why add a contingency buffer to the restoration period estimate?

Actual rebuild timelines routinely exceed initial estimates because of permitting delays, contractor availability, supply chain issues for materials or specialized equipment, and inspection cycles. Insurers and risk consultants commonly recommend adding 20–50% to your best-guess restoration timeline, which is why this calculator defaults to a 25% buffer.

What's the difference between business interruption and extra expense coverage?

Business interruption replaces the net income and fixed costs you lose while shut down. Extra expense covers additional costs you incur specifically to keep operating or reopen faster — renting temporary space, expediting equipment shipping, or paying overtime. Most policies bundle both, and this calculator includes a line for extra expense so you size the full picture.

Does business interruption coverage have a waiting period?

Yes, typically a 24-, 48-, or 72-hour deductible period (sometimes called a 'time deductible') during which no loss is paid, similar to how a dollar deductible works on property coverage. Shorter waiting periods cost more in premium, so match it to how much cash reserve you'd have on hand to bridge that gap.

Accuracy and limitations

  • Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
  • Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
  • This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.

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APA
RevenueLab. (2026). Business Interruption Coverage Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/business-interruption-coverage
HTML
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/business-interruption-coverage" target="_blank" rel="noopener">Business Interruption Coverage Calculator — RevenueLab</a> (2026).</p>
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Source: [Business Interruption Coverage Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/business-interruption-coverage) (2026).
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