Disability Insurance Income Need Calculator
Calculate monthly disability insurance benefit needed from gross income and expenses.
Returns coverage gap and recommended benefit at 60-70% income replacement.
The risk no one wants to think about
The Social Security Administration estimates that roughly 1 in 4 of today’s 20-year-olds will experience a disabling condition lasting 90+ days before reaching age 67. That’s higher than the lifetime risk of dying during working years. Yet most working adults carry no individual disability insurance beyond whatever short-term coverage their employer provides.
Disability insurance replaces a portion of your income if you can’t work due to illness or injury. The income you earn is almost certainly your largest financial asset — a 30-year-old earning $80,000 has roughly $2.4M of remaining lifetime earnings (before raises). Insuring that future income is at least as important as insuring your house or car.
The 60-70% replacement rule
Industry standard: disability benefits should replace 60-70% of gross income. The reason it’s less than 100%:
- Employer-paid LTD benefits are taxable income (the employer wrote off the premium)
- Privately-paid LTD benefits are tax-free (you paid premium with after-tax dollars)
So a 65% benefit from a personally-paid policy might actually replace 80-90% of your former take-home pay. From an employer-paid policy at the same 65%, you’d net closer to 50-55% of take-home — typically not enough to cover essential expenses.
This is a critical distinction: an employer’s “100% income replacement” sounds great until you factor in that taxes will eat 30-40% of it.
Short-term vs long-term disability
| Type | Duration | What it covers |
|---|---|---|
| Short-term disability (STD) | Up to 3-6 months | Pregnancy, surgery recovery, broken bones |
| Long-term disability (LTD) | 2 years to age 65 | Cancer, MS, mental health, chronic conditions |
| Catastrophic | Variable | Severe injuries, terminal illness |
STD is what people think of when they imagine disability insurance — and it’s the cheaper, more commonly carried coverage. But LTD is what actually protects retirement-level wealth. A 3-month broken leg costs roughly $15,000 in lost wages. A 25-year disabling condition starting at age 40 costs $2M+ in lost wages.
The elimination period — how it affects premiums
The “elimination period” is essentially the deductible — the waiting period from when disability starts until benefits begin:
| Elimination | Premium impact | Match with |
|---|---|---|
| 30 days | Highest premium | Minimal emergency fund |
| 60 days | High | 2-month fund |
| 90 days | Mid-range standard | 3-4 month fund |
| 180 days | Lower | 6 month fund |
| 365 days | Lowest | Substantial savings/wealthy |
The math: a 90-day elimination period typically costs 30-40% less than a 30-day. If you have 4-6 months of emergency fund, the longer elimination is the cost-effective choice.
What disability insurance actually pays (definitions matter enormously)
| Definition | What it means |
|---|---|
| Own occupation | Pays if you can’t perform YOUR specific job (best, most expensive) |
| Modified own occupation | Own-occ for 2-5 years, then reverts to any-occ |
| Any occupation | Pays only if you can’t work ANY job (worst, cheapest) |
The difference is huge. A surgeon with a hand injury can’t operate but could probably teach or consult. Under “own occupation” coverage, they collect full benefits. Under “any occupation” coverage, they don’t — they could earn $50k teaching, so they’re not “disabled” under the definition, even though they’ve lost a $400k surgical practice.
Pay extra for true own-occupation coverage if your profession is specialized (medicine, law, technical fields). It’s worth the 20-30% premium difference.
Premium estimates (2024 typical)
Long-term disability annual premium runs roughly 1-4% of the annual benefit, depending on:
| Factor | Premium impact |
|---|---|
| Age (younger = cheaper) | Substantial |
| Gender (women pay 30-50% more if gender-rated) | Significant |
| Health/medical history | Significant |
| Occupation class (Class 1 office worker vs Class 4 manual labor) | Huge |
| Smoking | Adds 20-50% |
| Benefit period (2-year vs to age 65) | 2-3x for full coverage |
| Definition (own-occ vs any-occ) | 20-30% premium |
| Elimination period (longer = cheaper) | 20-40% range |
| Cost-of-living adjustment rider | +10-15% |
A healthy 35-year-old engineer (Class 1 occupation) with $4,000/month benefit, 90-day elimination, to-age-65 benefit period, own-occupation, might pay $1,200-$1,800/year. Same person at $8,000/month: $2,400-$3,600/year.
Worked example
Software engineer making $9,000/month gross ($108k/year):
- Target 65% benefit: $5,850/month
- Employer LTD (60% of base salary): $5,400/month — close to target on paper
- BUT employer LTD is taxable, so effective benefit at 25% tax bracket: $4,050/month net
- Personal expenses: $4,500/month
- Gap: $4,500 − $4,050 = $450/month shortfall
Solution: buy a supplemental personal policy of $500-1,500/month with own-occupation definition. The tax-free $500-1,500 closes the gap and adds insurance against losing the job (which would also lose the employer LTD).
Annual premium estimate: $300-$600 for $1,000/month supplemental coverage.
Where Social Security Disability Insurance (SSDI) fits in
SSDI is a federal program that pays benefits if you can’t work due to a severe, long-term disability. It exists, but it has serious limitations as a substitute for private coverage:
- Strict definition: must be totally disabled from ANY substantial work — not just your job
- Long processing: 5-month wait minimum, often 1-2 years for approval
- Frequent denials: 65% of initial applications are denied
- Low benefits: average payment is roughly $1,500/month — not income replacement
- Asset limits do not apply (unlike SSI) but income limits do
SSDI is the safety net for catastrophic disability, not a substitute for private LTD coverage. Plan as if it doesn’t exist; treat it as a bonus if you eventually receive it.
The employer LTD trap
Many workers think “I’m covered through work” and stop there. Three reasons this is often wrong:
- Taxable benefit reduces effective payout by 25-35%
- Coverage ends if you leave the job — and you often can’t get individual coverage if you’re already sick (preexisting condition)
- Definitions are usually weak (modified own-occupation that becomes any-occupation after 24 months)
The smart move for high-income professionals: layer a personal own-occupation policy on top of employer LTD while you’re young and healthy. Premium is 1-3% of the benefit while you can lock in good terms.
When to buy
Buying disability insurance is heavily age-dependent:
| Age | Strategy |
|---|---|
| 20s-early 30s | Buy. Cheap, no health issues yet, locks in rates. |
| Mid 30s-40s | Buy now if not yet. Premium climbs sharply by year. |
| 50s | Possible but expensive; consider only if essential income |
| 60+ | Most insurers won’t sell new LTD policies |
Premium for the same coverage roughly doubles between ages 25 and 45. The cheapest time to buy is when you least feel you need it.
Bottom line
Disability insurance is one of the least-purchased and most-needed financial products. Individual LTD with own-occupation definition is the gold standard for professionals. Employer-provided coverage alone is rarely enough. Pricing scales with age, so the decision compounds — every year delayed costs roughly 5-10% more in premium for the same coverage.