A $4,000 Prenup to Protect a $200,000 Business Nets $37,000 in Expected Value
We ran a common scenario through the calculator: $200,000 of premarital business equity, a state where roughly half of that would likely be treated as divisible without a prenup, and the CDC/NCHS estimate that about 41% of first marriages end in divorce. The expected value of that risk — $41,000 — dwarfs the $4,000 attorney cost of drafting the agreement (most states require separate counsel for each party, so budget for two attorneys).
Where the math flips
| Premarital assets | Split share | Divorce probability | Expected risk | Attorney cost | Net expected benefit |
|---|---|---|---|---|---|
| $200,000 | 50% | 41% | $41,000 | $4,000 | +$37,000 |
| $15,000 | 50% | 41% | $3,075 | $4,000 | -$925 |
| $1,200,000 | 50% | 41% | $246,000 | $5,000 | +$241,000 |
The expected value scales linearly with the assets at stake — which means there’s a genuine breakeven point, not just a vague “it depends.” At a 50% split share and 41% divorce probability, the breakeven asset value is roughly $19,500: below that, the attorney cost likely exceeds the expected benefit; above it, the prenup pays for itself in expectation.
Why “expected value” is the right frame, not “will I get divorced”
Nobody enters a marriage planning to get divorced, which is exactly why framing a prenup as “do I expect this to happen” produces bad decisions — the honest answer is almost always no, and that answer says nothing about whether the insurance-like value of the agreement is worth its cost. The right question is closer to how you’d evaluate any other low-probability, high-consequence financial decision: multiply the potential loss by its probability, and compare that to the cost of protecting against it. A $200,000 business is exactly the kind of asset where that math tips decisively toward “worth the conversation.”
Where this framework breaks
- Little premarital wealth to protect. If both partners are starting from a similar, modest position, the expected benefit is small relative to the attorney cost no matter how the divorce probability is set.
- The real motivation isn’t financial. Some couples want a prenup purely for clarity and reduced future conflict — that value isn’t captured by an expected-value calculation built around dollar amounts.
- A strict separate-property state already protects premarital assets. If the realistic split-share estimate is genuinely low, the calculated benefit shrinks — though commingling risk over a long marriage can still erode that protection without documentation.
- Illiquid or hard-to-value assets (a business, real estate). A prenup with a clear valuation methodology is often worth more than the raw dollar-figure framing suggests here, since ambiguity itself becomes costly in a dispute.
What to actually do
- List premarital assets honestly — business equity, an inheritance, home equity — before estimating what a prenup would protect.
- Get a real attorney-fee quote for your state; costs vary with complexity and whether both parties need separate counsel (usually required for enforceability).
- Start the conversation early — most states require enough time before the wedding to avoid a later duress challenge.
- If the window before the wedding has closed, a postnuptial agreement applies the same asset-protection logic after marriage instead.
- Talk to a family-law attorney about your state’s specific execution requirements and what your split-share estimate should realistically reflect.
For the financial picture a prenup is meant to plan around, see why the real cost of divorce isn’t the lawyer, and for the tax-filing side of combining two incomes, see why the marriage tax penalty is mostly a myth.
Open the Prenup Cost-Benefit Calculator → and run your own premarital assets and state assumptions.
Quick answers
Is a prenup worth it financially?
It depends on how much premarital wealth is at stake relative to the attorney cost. Using expected value (assets at risk × the divorce probability), a $200,000 premarital business against a $4,000 attorney bill nets about $37,000 in expected benefit. A $15,000 premarital savings account against the same $4,000 cost nets only about -$925 — the cost can exceed the expected benefit at smaller asset values.
What percentage of marriages end in divorce?
About 41% of first marriages, per 2024 CDC/NCHS data — notably below the commonly cited but outdated '50%' figure, which reflected a divorce-rate peak around 1980 that has since declined significantly.
Do both partners need separate lawyers for a prenup?
In most states, yes — independent counsel for each party is one of the standard requirements for a prenup to hold up if challenged later, along with full financial disclosure and enough time before the wedding to avoid a duress claim.
What does a prenup NOT typically cover?
Child custody and child support terms are generally not enforceable in a prenup — courts decide those based on the child's best interests at the time, regardless of what a prenup says. Prenups mainly cover property division and spousal support terms.