Compares head-office overheads & profit claims for a period of prolongation using the Hudson, Emden and Eichleay formulas, plus a simple prelims build-up.
Indicative and comparative only: none of the formulas alone establishes entitlement to a claim.
Indicative and comparative only. Always confirm figures and admissibility with a qualified quantity surveyor or claims consultant before use in a formal claim.
About this loss and expense calculator
This free loss and expense calculator compares the three recognised head-office overheads & profit (HO&P) formulas. Hudson, Emden and Eichleay, for a period of compensable prolongation, alongside a simple time-related prelims build-up. It is aimed at quantity surveyors, contractors and claims consultants scoping a loss-and-expense or delay claim. Enter the contract sum and period, the tendered and actual overhead percentages, the Eichleay billings and overhead figures and the delay, and it returns each formula’s HO&P claim side by side. Everything runs in your browser. Nothing is uploaded.
How loss and expense is calculated
Hudson and Emden share a weekly-value intermediate, contract sum ÷ contract period, each applying its own HO&P percentage over the delay weeks: claim = (HO&P% ÷ 100) × weekly value × delay weeks. Hudson uses the tendered %, Emden the % from audited accounts. Eichleay is the three-step billings-ratio method: (contract billings ÷ total billings) × total overhead gives the allocable overhead, divided by actual contract days for a daily rate, times the compensable delay days. The prelims build-up is a non-formula comparator, prelims rate × delay weeks. Formula structure is cross-checked against SCL Paper 230 and FTI Consulting; Eichleay follows the original ASBCA doctrine.
Frequently asked questions
Which formula should I actually use?
Emden: using the actual overhead percentage from audited accounts. Is the version UK courts most often accept (for example Walter Lilly v Mackay). Hudson uses the tendered percentage and is criticised for double-counting profit already in the contract sum. Eichleay is a US federal-contracting doctrine rarely applied here. None of them alone proves entitlement. All require evidence of a resource that could not earn elsewhere.
Why does Eichleay use days when the others use weeks?
Because that is how each method is defined. Eichleay allocates overhead to a daily rate and multiplies by the compensable delay in days; Hudson and Emden work in weekly contract value and delay weeks. Enter the delay in the unit each panel asks for, the calculator keeps them separate so the comparison stays true to each published formula.
Does a figure here substantiate a claim?
No. These are indicative comparators to show the order of magnitude and how the methods diverge, not a substantiated claim or legal advice. Entitlement to unabsorbed overheads must be proved on the facts, and admissibility varies by contract and jurisdiction. Confirm both the figures and their admissibility with a qualified quantity surveyor or claims consultant.