Margin Leak Calculator
Construction runs on thin margins, and variations are where they quietly disappear. Work gets done, the claim never lands in full, and the shortfall only shows up at final account.
Put in four numbers you already know and see what under-recovered variations are costing you every year, then the figure that really stings: what that loss represents as a share of your bottom line.
How much margin are you leaking?
Four inputs. One number you won't forget.
Construction net margins typically sit around 2 to 6%.
Industry benchmark: typically 5 to 12% of contract value.
The share of variation value you never recover, through missed claims, negotiation or write-offs.
What You Need
Four numbers you already know
No commercial data to dig out and no sign-up to get your figure. Enter four inputs and the calculator does the rest, instantly. Not sure on a number? Use the industry benchmarks built into the tool.
- Annual turnover: Your total annual revenue across all projects
- Typical net margin: Your usual net profit margin as a percentage
- Variation volume: Variations as a percentage of contract value (benchmark 5 to 12%)
- Under-recovery rate: The share of variation value you never recover
Where The Margin Goes
Why variations quietly erode your profit
Under-recovery is rarely one big event. It is dozens of small leaks across the year that never get captured, priced or chased.
Work proceeds before the variation is priced
A verbal instruction keeps the job moving, the cost is incurred, and the value is negotiated down months later when your leverage has gone.
Variations are never formally captured
Without a live register, small variations slip through entirely. They are never claimed because no one logged them in the first place.
The leak is invisible until final account
On a spreadsheet-driven process, the gap between applied-for and certified value on variations is never tracked, so it surfaces only when it is too late to recover.
StoneRise Commercial
Recover the margin you have already earned
StoneRise Commercial was built by quantity surveyors who ran construction businesses and lost margin to exactly this problem. It captures every variation the moment it arises, prices it against the contract, and tracks recovery through to certification.
The result is simple: the value you earn becomes the value you recover, and the leak this calculator just quantified stops being invisible.
Every variation captured
Instructed, proposed or disputed, each variation is logged against the contract the moment it arises, with its value and status.
Priced before the work is done
Variations are priced and submitted up front, protecting the margin you calculated instead of negotiating it away later.
Recovery tracked in your live CVR
Applied-for versus certified value on variations is a live figure, with early-warning alerts the moment the gap widens.