Rex says
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
Monthly benefit gap to insure
$1,456.00
After-tax employer benefit
$3,744.00
Annual shortfall
$17,472
Expenses covered today
72.0%
Share of expenses uncovered
28.0%
Gross employer benefit
$4,800.00
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter gross monthly income ($).
- 2Enter essential monthly expenses ($).
- 3Enter employer benefit (% of income).
- 4Enter employer benefit taxed?.
- 5Enter effective tax rate (%).
- 6Enter other monthly income ($).
- 7Read your monthly benefit gap to insure on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Own-occupation disability policies typically replace 60% of gross income, and benefits are tax-free when you pay the premium yourself — which changes how much coverage you actually need.
Worked example
Using the values the calculator loads with:
Inputs
- Gross monthly income: 8000 $
- Essential monthly expenses: 5200 $
- Employer benefit: 60 % of income
- Employer benefit taxed?: Yes (employer-paid)
- Effective tax rate: 22 %
- Other monthly income: 0 $
Results
- Monthly benefit gap to insure: $1,456.00
- After-tax employer benefit: $3,744.00
- Annual shortfall: $17,472.00
- Expenses covered today: 72.0%
- Share of expenses uncovered: 28.0%
- Gross employer benefit: $4,800.00
What each field means
Inputs
- Gross monthly income ($)
- The gross monthly income used in the calculation, measured in $. Starts at 8000 $ so you have a working example on load.
- Essential monthly expenses ($)
- The essential monthly expenses used in the calculation, measured in $. Starts at 5200 $ so you have a working example on load.
- Employer benefit (% of income)
- The employer benefit used in the calculation, measured in % of income. Starts at 60 % of income so you have a working example on load. Accepted range: 0–100 % of income.
- Employer benefit taxed?
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (employer-paid), No (you pay premiums).
- Effective tax rate (%)
- The effective tax rate used in the calculation, measured in %. Starts at 22 % so you have a working example on load. Accepted range: 0–50 %.
- Other monthly income ($)
- The other monthly income used in the calculation, measured in $. Starts at 0 $ so you have a working example on load.
Results
- Monthly benefit gap to insure
- 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.
- After-tax employer benefit
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Annual shortfall
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Expenses covered today
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Share of expenses uncovered
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Gross employer benefit
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the disability insurance needs calculator work?
Own-occupation disability policies typically replace 60% of gross income, and benefits are tax-free when you pay the premium yourself — which changes how much coverage you actually need. The underlying maths is: Gap = Monthly expenses − (employer benefit + other income).
What do I need to enter?
6 values: gross monthly income, essential monthly expenses, employer benefit, employer benefit taxed?, effective tax rate, and other monthly income. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the monthly benefit gap to insure result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
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.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Disability Insurance Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/disability-insurance-needs
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/disability-insurance-needs" target="_blank" rel="noopener">Disability Insurance Calculator — RevenueLab</a> (2026).</p>
Source: [Disability Insurance Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/disability-insurance-needs) (2026).