Duxbury Calculations in Divorce: What They Are and When to Use Them
Financial settlements in divorce can be complex, particularly when considering the long-term needs of one party. One of the most established tools used by family lawyers and the courts to capitalise spousal maintenance into a lump sum is the Duxbury calculation. But what is the Duxbury formula, and is it the right option for your divorce?
In this guide, we’ll explore how Duxbury calculations work, when they are used, their benefits and limitations, and how they apply in high net worth divorce cases. Whether you're considering a clean break or evaluating ongoing spousal maintenance, understanding this model is essential.
What Is a Duxbury Calculation?
A Duxbury calculation is a method used in family law to convert future spousal maintenance payments into a single lump sum. It was established in the landmark case Duxbury v Duxbury and has become a common tool in divorce settlements in England and Wales.
The goal of the Duxbury model is to calculate a capital sum that, when invested and drawn upon over time, will provide the receiving party with a regular income for life—without leaving a surplus or deficit at the end of their expected lifespan. This approach aims to strike a balance between fairness and financial independence.
When Are Duxbury Calculations Used in Divorce?
Duxbury calculations are typically used when one or both of the parties prefers, or the court orders, a lump sum payment instead of ongoing maintenance. This often arises in cases where:
The paying party seeks a clean break.
There’s a desire to avoid the ongoing contact and potential conflict tied to regular payments.
The recipient wants financial certainty and autonomy.
One or both parties want to minimise the need for future court involvement.
Capitalising maintenance through the Duxbury model can be a practical solution, particularly where there is enough capital to support this approach.
How Does a Duxbury Calculation Work?
The Duxbury formula involves a detailed financial projection using various actuarial assumptions. These include:
Life expectancy of the recipient.
Net return on investment (after inflation and tax).
The annual income needed to meet the recipient’s needs.
Taxation on income drawn from the lump sum.
For example, if a recipient needs £100,000 annually and is expected to live for another 30 years, the Duxbury model calculates the lump sum needed to meet that need through prudent investing and controlled drawdown.
Duxbury tables, updated periodically, provide multipliers based on age and assumed return rates, provide these calculations for legal practitioners.
Pros and Cons of Using the Duxbury Model
Advantages:
Finality: Achieves a clean break with no further financial ties.
Certainty: Provides both parties with clarity on their future finances.
Reduced conflict: No ongoing payments that can trigger disputes given the ability for either party to seek a variation of ongoing maintenance during its term.
Disadvantages:
Assumption-dependent: Heavily reliant on financial assumptions about inflation, return rates, and longevity.
Risk of under- or over-compensation: Market changes or longer-than-expected lifespan can deplete funds early.
One-size-fits-all: May not account well for fluctuating needs or income. Inevitably it is a useful tool, rather than providing the “right answer” to every case.
The Duxbury calculation may work well in many cases, but it’s not always appropriate—particularly in unpredictable economic climates or where health, age, or lifestyle factors are variable.
Recent Updates to Duxbury Tables
The Duxbury tables are not static. In recent years, they have been updated to reflect changing economic conditions, including lower expected returns on investment, investment management charges and shifting inflation rates.
As of the latest updates, the assumed real rate of return (after inflation and tax) has decreased, meaning higher lump sums are now needed to achieve the same level of income. This has important implications, particularly in high-value divorces where even slight shifts in assumptions can alter settlements significantly.
Family lawyers and clients alike should ensure they are using current data and assumptions when using Duxbury.
Duxbury Calculations in High Net Worth Divorces
In cases involving £5 million or more in assets, capitalised maintenance calculations can become more nuanced. High net worth individuals may have:
Complex asset portfolios.
Business interests or carried interest in private equity.
International assets and tax considerations.
In these cases, the standard Duxbury model may not reflect the true financial dynamics of the parties. Lifestyle expectations, access to wealth, and potential for asset growth must all be considered.
Bespoke actuarial assessments may be more appropriate than relying solely on the Duxbury tables, which can account for the individual circumstances of your case.
Alternatives to Duxbury Calculations
While Duxbury is widely used, it is not suitable for every divorce. Alternatives include:
Ongoing periodical payments, which may be reviewed over time.
Hybrid models combining ongoing periodical payments which terminate upon the payment of lump sums.
Tailored financial settlements based on unique needs and financial modelling.
In some cases, particularly where income fluctuates or the recipient is young, a traditional spousal maintenance order with a specific term may offer greater fairness and flexibility.
Do I Need Legal Advice on Duxbury Calculations?
Yes—calculating and negotiating a fair lump sum using the Duxbury model requires specialist legal and financial advice.
At Ribet Myles, our family law team works with leading financial experts to assess the accuracy and appropriateness of any Duxbury-based offer or bespoke calculations tailored to your individual circumstances.
We help clients understand:
When Duxbury is likely to be applied or whether another approach is preferable.
Whether it benefits them in the long run.
How to challenge or propose alternative solutions when needed.
We also ensure any agreement reflects your lifestyle, financial goals, and future needs—especially in complex or high-value cases.
Conclusion: Is a Duxbury Calculation Right for You?
The Duxbury model can be a powerful tool in divorce settlements—but it is important to remember that it is not one-size-fits-all. Whether you are negotiating a clean break, seeking long-term financial stability, or dealing with a complex portfolio of assets, it's essential to approach Duxbury calculations with expert guidance and up-to-date financial insight.
If you’re going through a divorce and want to understand your options around spousal maintenance or capitalised settlements, contact Ribet Myles on 020 7242 6000. Our team of specialist family lawyers can advise on whether a Duxbury calculation is right for your case and help secure the financial outcome you need.
To speak to an experienced family lawyer about your case call us on 020 7242 6000.