Glossary
Net Saving vs Gross Saving
Direct Answer / TL;DR
What is Net Saving vs Gross Saving?
Gross saving is the raw price difference multiplied by your fill volume. Net saving subtracts the fuel cost of driving to the cheaper station. Only the net saving is money you actually keep.
Why does it matter for UK drivers?
The distinction between gross and net saving is what makes WorthThePump different from every other fuel price app. Most apps show you the cheapest price, but they don't tell you whether it's actually cheaper once you account for getting there.
Gross saving = (local price − cheap price) × litres filled. If you fill 50 litres and the cheap station is 5p/L less, your gross saving is £2.50.
Net saving = gross saving − detour fuel cost. If the cheap station is 2 miles off your route in a car doing 35 MPG at 145p/L, the 4-mile round-trip detour costs (4 × 145 × 4.546 ÷ 35) ÷ 100 = 75p. So your net saving is £2.50 − £0.75 = £1.75.
But the reality is more nuanced. If the cheap station is on your planned route, the detour cost is zero — your gross saving equals your net saving. If it's a dedicated trip with no other errands, you should factor in the full return journey. WorthThePump uses the straight-line (Haversine) distance from your current location to the station as the detour estimate — which is a conservative approximation that assumes you're going out of your way.
The net saving figure is the number displayed prominently in WorthThePump results. A green 'Worth It' verdict means the net saving is positive — the station is genuinely cheaper once the fuel cost of getting there is factored in. A red 'False Economy' verdict means you'd actually spend more by going there.
Over a year, small per-fill net savings compound significantly. Saving £1.50 per fill, filling up weekly, adds up to £78/year — enough to notice on a household budget.
Related terms
Further reading
Now you know what Net Saving vs Gross Saving means —
find out if your nearest cheap station is actually worth the trip.