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Lump Sum vs Monthly Alimony Calculator

Calculate the present value of monthly alimony payments and compare to a lump sum buyout offer — find the fair settlement amount for both parties.

Updated April 2026 PV Analysis + TCJA Tax Private — runs in your browser
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The discount rate converts future payments to today's dollars. Using 5–7% reflects typical investment returns. A higher rate makes monthly payments worth less in present value, making a lump sum relatively more attractive to the payee.
Monthly Payment Schedule Analysis
$2,200/mo
Total Nominal Payments$184,800
Present Value Today$155,654
Duration7 years
Discount Rate Used5%
The present value of $184,800 in future payments discounted at 5% is $155,654. This is the economically equivalent lump sum today. Any buyout offer should be compared to this figure.
Advanced Calculator

NPV comparison chart across durations, discount rate sensitivity table, and year-by-year value breakdown.

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Monthly PV at 5%
$173,777
Gross total: $211,200
Lump Sum Offer
$160,000
Offer is $13,777 below PV — bad for payor
$0$50,723$101,446$152,169$202,892OfferDuration (years) — dot = your input
Break-even discount rate7.2% (where PV = offer)
VerdictMonthly is more valuable
PV − Offer+$13,777
Professional Simulator

Investment return modeling, risk-adjusted NPV with remarriage/modification probabilities, and lifetime growth chart.

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Payor Perspective
Monthly PV: $173,777
Lump sum: $160,000
Monthly costs more by $13,777
Payee Perspective
Monthly PV: $173,777
Lump sum: $160,000
Monthly is worth more by $13,777
Key Metrics
Gross total payments$211,200
Present value at 5%$173,777
Lump sum discount to PV7.93%
Lump sum FV at 7% return$274,910
Monthly FV at 7% return$283,683

Lump Sum vs Monthly Alimony: The Core Trade-off

When divorcing spouses negotiate alimony, they face a fundamental question: periodic monthly payments or a one-time lump sum buyout? Each structure has distinct financial, legal, and practical implications for both parties. The financially rational comparison uses present value analysis — converting the stream of future payments into today's equivalent dollars.

A lump sum eliminates uncertainty for both parties. The payor closes out the obligation permanently. The payee gets immediate, risk-free cash. But the right number depends on the discount rate, duration, and the parties' respective risk tolerances.

Present Value Formula

Present Value of Monthly Payments: PV = M × [1 − (1 + r)^−n] ÷ r Where: M = Monthly alimony payment r = Monthly discount rate (annual rate ÷ 12) n = Total months (years × 12) Example (5% annual rate): Monthly: $2,200 for 7 years r = 5% ÷ 12 = 0.4167%/month n = 84 months PV = $2,200 × [1 − (1.004167)^−84] ÷ 0.004167 PV ≈ $160,700 Any lump sum offer should be compared to this PV: Offer > PV: Payor paying premium (payee benefits) Offer < PV: Payor getting discount (payor benefits) Offer = PV: Economically equivalent to monthly payments

Example: $2,200/Month for 7 Years

Lump Sum vs Monthly Comparison at 5% Discount Rate

Monthly payment$2,200/mo
Duration7 years (84 months)
Nominal total$184,800
Present value at 5%~$160,700
Discount from nominal−$24,100 (13% discount)
Lump sum offer: $150,000$10,700 below fair value
Lump sum offer: $175,000$14,300 above fair value

A $160,700 lump sum is mathematically equivalent to 7 years of $2,200 payments at a 5% discount rate. The payor should prefer any lump sum below this figure; the payee should prefer any lump sum above it — everything else being equal.

Official Sources & References

Frequently Asked Questions

It depends on the goals of each party. For the payor, a lump sum eliminates ongoing obligation, enforcement risk, and future modification litigation. For the payee, a lump sum provides immediate certainty and eliminates risks of payor default, bankruptcy, income loss, or death. The financially "better" option depends on the discount rate and whether the offered amount is above or below the present value of the monthly stream.
For divorces finalized after December 31, 2018, neither periodic nor lump sum alimony is deductible by the payor or taxable to the recipient under the TCJA. For pre-2019 divorces, periodic alimony was deductible/taxable but lump sums classified as property settlements (not alimony) were generally not deductible. In all cases, lump sums that are clearly property division — not designated as alimony — are tax-neutral for both parties.
The discount rate reflects what both parties believe money is worth over time. Common approaches: use the expected investment return rate (5–7% for diversified portfolios), use a risk-free rate (current Treasury yield, ~4–5%), or use the inflation rate (2–3% for conservative calculations). A higher discount rate reduces the present value of future payments, making lump sums relatively more attractive. Courts sometimes use the prime rate or Treasury rates in formal proceedings.
Yes, in most states parties can agree post-divorce to convert periodic alimony to a lump sum buyout. Both parties must consent, and the agreement should be submitted to the court for approval and incorporated into a modified order. Without court approval, an informal payment may still leave the original order technically in force. Some states allow this more readily than others — consult an attorney in your state.
If a lump sum alimony payment has already been made, it is not returned if the recipient later remarries. This is one of the key advantages of a lump sum for the payee — it provides certainty and is not subject to termination events. For periodic payments, remarriage terminates alimony in all US states, cutting off the recipient's future payments. This risk is eliminated when a lump sum is accepted upfront.

When to Consult a Family Law Attorney or CDFA

Present value math is only one factor in a lump sum vs monthly decision. Consult a family law attorney or Certified Divorce Financial Analyst (CDFA) if your case involves: significant uncertainty about the payor's ability to pay over time, tax treatment questions under TCJA (whether lump sum is deductible/taxable for pre-2019 divorces), retirement accounts subject to QDRO, or cohabitation clauses that would terminate monthly support. A CDFA can model the full financial trajectory of each option including investment returns, tax impact, and risk-adjusted value.

Related Calculators

General Alimony Calculator
Estimate the monthly amount that the lump sum should replace
Alimony Tax Impact Calculator
Understand post-TCJA tax treatment before negotiating buyout
Alimony Duration Calculator
Know how many years of payments the lump sum needs to cover
Alimony Modification Calculator
A lump sum eliminates modification risk — calculate what you might lose
Not legal or financial advice. This calculator provides estimates based on published guidelines and formulas. Family law varies by jurisdiction and individual circumstances. Always consult a qualified attorney or financial advisor before making decisions. Full disclaimer · Our methodology