Prenup vs. No Prenup Calculator

Compare what each spouse keeps in a divorce scenario with and without a prenuptial agreement, based on your assets, income, and state property laws.

Updated April 2026 UPAA · UPMAA · State Property Law Private — runs in your browser

Spouse A Pre-Marital Assets

Assets owned before marriage

Spouse B Pre-Marital Assets

Annual Joint Savings

Combined savings per year during marriage

Years Married (Scenario)

Spouse A Annual Income

Spouse B Annual Income

Spouse A Business Value

0 if no business

Asset Appreciation Rate

Asset Division WITH Prenup (Divorce Scenario)

$428,636 Spouse A keeps

Spouse A Keeps$428,636

Spouse B Keeps$128,588

Marital Assets (split)$150,000

A's Pre-Marital (protected)$200,000

B's Pre-Marital (protected)$50,000

Advanced Analysis

Outcome comparison across 3 divorce scenarios, state rules reference table, and sensitivity analysis by asset gap.

Show Advanced Tools ▼

Spouse A Pre-Marital Assets

Spouse A Business Value

Annual Joint Savings

Property System

Spouse A Outcome — With Prenup vs. Without (Equitable Distribution)

Short Marriage (3 yrs)

With Prenup$577,288

Without Prenup$404,750

Prenup benefit: +$172,538 for Spouse A

Mid Marriage (10 yrs)

With Prenup$788,668

Without Prenup$462,500

Prenup benefit: +$326,168 for Spouse A

Long Marriage (20 yrs)

With Prenup$1,195,989

Without Prenup$545,000

Prenup benefit: +$650,989 for Spouse A

Professional Tools

Monte Carlo divorce probability model, lifetime financial impact, estate planning interactions, and international asset protection.

Show Professional Tools ▼

Spouse A Pre-Marital Assets

Business Value at Marriage

Annual Joint Savings

Marriage Duration (scenario)

Property System

Expected Value Model — Prenup Decision

$150,579 expected value

Prenup Benefit if Divorced$537,781

Divorce Probability (10 yrs)28%

Expected Value (EV)$150,579

Prenup Cost (est.)$8,000

Net EV$142,579

ROI on Prenup Cost6622%

Expected Value at Different Divorce Probabilities

Divorce Probability	Expected Value	Net EV (after cost)	Decision
10%	$53,778	$45,778	Get prenup
20%	$107,556	$99,556	Get prenup
30%	$161,334	$153,334	Get prenup
40%	$215,112	$207,112	Get prenup
50%	$268,890	$260,890	Get prenup

How a Prenup Changes What You Keep in a Divorce

A prenuptial agreement's primary financial function is to override default state property division laws in case of divorce. Without a prenup, state law determines how assets are split. With a prenup, you and your spouse decide in advance — giving both parties clarity and potentially very different financial outcomes.

Two Property Division Systems

Equitable Distribution (41 states): Courts divide assets "fairly" — typically 50/50 for marital assets, but courts have discretion. Pre-marital assets are generally protected.

Community Property (9 states: CA, TX, AZ, NV, WA, ID, LA, NM, WI): All assets acquired during marriage are split 50/50. Pre-marital assets are separately owned, but appreciation may be shared.

What a Prenup Can and Cannot Do

Prenup Can Protect / Define

Pre-marital assetsYes — keep what you came with

Business interestsYes — protect your business

Inheritance rightsYes — protect expected inheritance

Debt allocationYes — assign pre-marital debt

Alimony amountYes — waive or cap spousal support

Child custody/supportNo — courts decide this

Future child supportNo — not enforceable

Official Sources & Legal References

Frequently Asked Questions

Does a prenup actually protect your assets if you divorce? ▼

A well-drafted, properly signed prenup with independent counsel for both parties is generally enforceable and does protect pre-marital assets. Courts can overturn prenups for: procedural issues (signed under duress, rushed), lack of full financial disclosure, unconscionable terms, or failure to follow state-specific signing requirements. In states that have adopted the Uniform Premarital Agreement Act, enforcement standards are clear and consistent.

Who benefits more from a prenup — the wealthier or less wealthy spouse? ▼

Conventionally, prenups benefit the wealthier spouse by protecting pre-marital assets. However, well-negotiated prenups can benefit both parties. A clear financial agreement reduces ambiguity, making divorce proceedings shorter and cheaper. A prenup can also protect the lower-earning spouse by guaranteeing minimum spousal support or a defined share of marital assets, which a court might award less than expected.

What happens to a business during divorce without a prenup? ▼

Without a prenup, a business started or grown significantly during marriage can be treated as marital property and split in divorce. The non-owner spouse may receive up to 50% of the business's value, which could force a sale. Even a business started before marriage may be partially marital if its value increased significantly during the marriage. A prenup can define the business as separate property and prevent this outcome.

Can a prenup eliminate alimony obligations? ▼

In most US states, a prenup can waive, limit, or cap spousal support. However, some states (including California and New York under certain conditions) will not enforce alimony waivers that would leave one spouse on public assistance, or that are deemed unconscionable given the length of the marriage. A balanced prenup might waive alimony for short marriages but guarantee some support for marriages over 10 years.

Does discussing a prenup hurt the relationship? ▼

Research and therapist surveys consistently show that couples who discuss finances openly before marriage — including prenup conversations — have lower divorce rates and higher relationship satisfaction. A prenup conversation forces full financial disclosure, clarifies expectations, and demonstrates trust through transparency. The discomfort of the conversation is often less about the prenup itself and more about underlying financial anxieties that are better addressed before marriage than after.

When to Consult a Family Law Attorney

Consult a licensed family law attorney before deciding whether a prenuptial agreement is right for your situation. An attorney can assess whether your state's property division laws already protect your assets adequately, advise on enforceability standards in your state, and help draft an agreement that accurately reflects your intentions. Both parties should have independent counsel — this protects the agreement from later challenge and ensures each spouse fully understands what they are agreeing to.

Prenup vs. No Prenup Calculator

How a Prenup Changes What You Keep in a Divorce

Two Property Division Systems

What a Prenup Can and Cannot Do

Prenup Can Protect / Define

Frequently Asked Questions

When to Consult a Family Law Attorney

Related Calculators