Employer calculator
Grey fleet cost calculator
Estimate how much employees using their own cars for work really costs you; then model the savings and carbon impact of moving them into EV salary sacrifice.
What we mean by “grey fleet”
Grey fleet is the catch-all term for employees using their own cars for business travel. The visible cost is mileage reimbursement; the hidden cost is duty-of-care exposure, insurance gaps, and carbon reporting impact in Scope 3.
This calculator gives a guidance-grade view of annual spend and tailpipe CO₂, and shows what happens when some of those miles move to employer-provided electric cars via salary sacrifice.
Inputs
Use your best estimate. Defaults align to common UK policy.
Typical HMRC approved rate is £0.45 per mile for the first 10,000 miles.
A simple uplift to reflect insurance checks, compliance processes, incident risk, and admin overheads.
Use your own data if you have it; this is a typical ICE average.
Current grey-fleet spend
Mileage reimbursement plus a simple uplift.
Miles displaced by EV salary sacrifice
Assumes displaced miles become tailpipe-zero.
This doesn’t include productivity gains, reduced incidents, or employer NIC savings on the benefit.
Tailpipe CO₂ impact (Scope 3 commuting and business travel)
Guidance-grade; your reporting may use different factors.
What counts as “cost”
Why salary sacrifice helps
Use this in your business case
Want a tailored grey-fleet reduction plan?
If you are preparing an EV salary sacrifice roll-out, I can help you quantify grey-fleet baseline, build the carbon narrative for SECR reporting, and set up compliant duty-of-care processes.