How to Calculate Prenuptial Asset Protection
What is Prenuptial Asset Protection?
A prenuptial agreement asset calculator helps couples inventory and categorize their pre-marriage assets, debts, and expected inheritances to inform a fair prenuptial agreement. It distinguishes between separate property and what might become marital property.
Formula
Net Separate Property = Total Pre-Marriage Assets – Pre-Marriage Debts
- A_s
- Separate Assets ($) — Total value of pre-marriage assets
- D_s
- Separate Debts ($) — Total pre-marriage debts
- NSP
- Net Separate Property ($) — Assets minus debts brought into the marriage
Step-by-Step Guide
- 1List each partner’s pre-marriage assets: real estate, investments, retirement, business interests
- 2List each partner’s pre-marriage debts: student loans, credit cards, mortgages
- 3Calculate net separate property for each partner
- 4Identify assets likely to appreciate during marriage and decide how growth is treated
Worked Examples
Input
Partner A: $300,000 home, $50,000 investments, $80,000 student loans
Result
Net separate property: $270,000
Input
Partner B: $20,000 savings, $500,000 expected inheritance, $30,000 car loan
Result
Net separate property: $490,000 (including future inheritance protection)
Common Mistakes to Avoid
- ✕Not disclosing all assets — this can invalidate the entire prenup
- ✕Failing to account for appreciation of separate property during marriage
- ✕Not updating the prenup as circumstances change (postnuptial amendment)
Frequently Asked Questions
Are prenups enforceable?
Yes, in all 50 states, provided both parties made full financial disclosure, had independent legal counsel (or waived it), and signed voluntarily without duress.
How much does a prenup cost?
Typically $2,500–$10,000 total for both attorneys, depending on complexity. Each party should have their own attorney for enforceability.
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