dilutioncalculator.co.uk§ Verified 20 Jun 2026 · Reviewed by A. Hargreaves, MChem (Hons)
UK metric defaults
UK trade and lab work both run in millilitres and litres. The calculator defaults to ml because every retail trigger spray, mop bucket and drum sold in the UK is labelled in ml or L.
§ 1UK vessel sizes
- 500 ml spray, 750 ml trigger spray, 1 L bottle.
- 5 L mop bucket (standard janitor cart), 10 L bucket (heavy work).
- 25 L drum (standard trade pack), 200 L IBC.
- Watering cans typically 5 L or 10 L. Knapsack sprayers typically 10 L.
§ 2Mixing US and UK labels
A US label that asks for "2 fl oz per gallon" can mean either UK or US units depending on origin. US fl oz is 29.6 ml; UK fl oz is 28.4 ml. US gallon is 3 785 ml; UK gallon is 4 546 ml. Cumulative error on a knapsack-scale recipe is several percent.[15]
The safe route is to convert the ratio first. "2 fl oz per US gallon" is approximately 1:64. Use 1:64 in your UK 5 L bucket and you will get 76.9 ml of concentrate, which is the right dose.
§ 3When imperial is the right call
- ABV blending where HMRC spirit-strength tables use UK proof history.
- Heritage building specifications quoting pints of lime mortar.
- Imported US-only equipment with a dosing pump calibrated in fl oz.