Free Tools
Disability Benefit
Calculators
Honest estimates of your SSDI back pay and monthly benefit — built by disability attorneys, not marketers. Free. No email required.
Tool
SSDI Back Pay Calculator
Estimate retroactive and back pay based on your onset date and application date.
Open →Tool
Monthly SSDI Benefit Estimator
How much SSDI will you get per month in 2025? Estimate based on earnings.
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SSI vs SSDI Eligibility Check
Find out which program — SSDI, SSI, or both — fits your work history and finances.
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Disability Application Timeline
How long the SSDI / SSI process takes from application to approval.
Open →How SSDI back pay actually works
SSDI back pay is calculated from your established onset date (EOD) — the date the SSA agrees you became disabled — plus a mandatory 5-month waiting period, up to a maximum of 12 months retroactive to your application date.
That EOD is where having an attorney changes the dollar amount of your check. SSA defaults to the latest EOD they can defend. We argue for the earliest EOD the medical record supports.
SSI back pay is different
SSI has no retroactive months. Back pay starts from your application date. That makes filing date — and not delaying — critical for SSI claimants.
Real numbers, not marketing math
The average SSDI benefit in 2025 is roughly $1,580/month. The maximum is $4,018/month. Your specific PIA depends on your top 35 years of indexed earnings.
Frequently asked questions
How accurate is the SSDI back pay calculator?+
Our calculator uses the SSA's actual back pay formula — established onset date, application date, and the 5-month waiting period — so the estimate matches what SSA will issue. The exact dollar figure depends on your work-credit-based PIA, which we confirm during a free case evaluation.
How is SSDI back pay calculated?+
SSDI back pay = your monthly benefit × the number of months between your established onset date (plus the 5-month waiting period) and your approval date, capped at 12 months prior to your application date. SSI back pay starts from your application date with no retroactive months.
How much does SSDI pay per month in 2025?+
The 2025 average SSDI benefit is roughly $1,580/month. The maximum is $4,018/month at full retirement age. Your specific benefit depends on your lifetime earnings (your Primary Insurance Amount, or PIA).
Do these calculators replace a free case evaluation?+
No. The calculators give you a realistic estimate, but actual back pay depends on the established onset date your case secures — which is where having an attorney materially changes the result.