Source: https://www.quantsurv.com/library/tools/head-office-overheads-calculator
Content format: Markdown version of the public page.
Content reviewed: 2026-10-11

Interactive forms, calculators and booking actions require the linked web page. Any displayed calculation is the page's initial example, not a calculation for your circumstances.

# Head office overheads calculator

Compare the Hudson, Emden and Eichleay formulas on your own figures, side by side, with the working shown for each.

by [Jack Butler-Kettle](<https://www.quantsurv.com/about#jack-butler-kettle>) · About 4 min readShare

## How to use it

Head office overheads are the costs of running your business that each job helps to pay for, such as offices, directors and insurance. When a job overruns, it can tie up your firm without earning more towards them.

Enter an evidenced period relevant to the loss you are examining. An extension of time does not itself establish financial entitlement. This tool neither analyses delay nor proves recoverable loss.

Count periods in

Use the same unit for every period below.

Your contract

Contract sum (£)

The original sum, without VAT.

Original contract period (weeks)

The period in your contract, before any delay.

Period of delay (weeks)

Use the evidenced period relevant to the loss, which may differ from an extension of time. We do not analyse delay or entitlement.

For Hudson

Head office overheads and profit in your tender (%)

The percentage your tender added for them.

For Emden

Head office overheads and profit for the year (£)

From your company's accounts.

Turnover for the same year (£)

From the same accounts.

For Eichleay

Billings on this contract (£)

What you billed on it over its actual period.

Your total billings over the same period (£)

Across all your work.

Your head office overheads over the same period (£)

The actual costs, not a percentage.

Actual period of the subcontract (weeks)

From start to finish, including the delay.

### The working

#### Hudson

Your tender percentage.

Enter your contract figures and your tender percentage.

#### Emden

The percentage from your accounts.

Enter your contract figures and the two figures from your accounts.

#### Eichleay

Your actual overheads, shared out by billings.

Enter the period of delay and the four Eichleay figures.

The formulas are an approximation, not a record of what you actually lost. A formula claim usually also needs evidence that the delay stopped you taking other work.

This is for guidance only. It applies the formulas to your inputs; it does not establish a compensable period or work out the delay.

## Understanding your results

Compare the formula outputs with the actual overhead evidence and the circumstances of the delay. A formula estimate is not proof of loss or entitlement. Keep the input sources and explain why the selected method is appropriate; do not add overlapping recovery twice.

## How it works

**Hudson** takes the head office overheads and profit percentage in your tender. It applies it to the contract sum per week, or per day, then multiplies by the period of delay.

**Emden** works the same way, but takes the percentage from your company’s accounts: total head office overheads and profit divided by total turnover.

**Eichleay** shares out your actual head office overheads by this contract’s share of your billings over the actual period. It divides that by the actual period of the work, then multiplies by the period of delay.

Each step is rounded as it is shown: money to the penny, and percentages to two decimal places. So the working adds up when you check it.

The formulas are an approximation, not a record of what you actually lost. A formula claim usually also needs evidence that the delay stopped you taking other work. The High Court said so in [Walter Lilly & Company Ltd v Mackay](<https://caselaw.nationalarchives.gov.uk/ewhc/tcc/2012/1773>), at paragraph 543.

Hudson uses your tender percentage, while Emden uses your accounts. Eichleay originated in the United States. No formula is automatically appropriate for your contract claim.

Use your records first where they show the actual cost, such as director time spent on the delay. A formula does not replace evidence of entitlement, causation and actual loss.

[Delay and disruption cost recovery](<https://www.quantsurv.com/claims?service=%2Fdelay-and-disruption%2Fservices%2Fdelay-disruption-recovery#client-types>) considers the calculation alongside the event records and contractual basis, rather than treating the formula result as an established entitlement.

## Sources

1.  [Walter Lilly & Company Ltd v Mackay & Anor \[2012\] EWHC 1773 (TCC) (High Court, Technology and Construction Court, 11 July 2012)](<https://caselaw.nationalarchives.gov.uk/ewhc/tcc/2012/1773>). The National Archives, Find Case Law.

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