Long and crisp
One part gin to three parts tonic
Tanqueray publishes 50ml gin with 150ml premium tonic. It is an easy first test when the tonic is cold and the glass has plenty of ice.
Free measured-serve calculator
Gin and tonic ratio calculator
Compare two producer-published starting serves or enter your own. Get the exact gin and tonic quantities, shopping packs, cost, estimated finished strength and UK alcohol units.
Measured ratiosCustom shelf pricesNo sign-up
Build the serve
Add your current shelf prices
Your measured plan
1 : 3
gin to tonic
50ml + 150ml
- Gin required
- 200ml
- Tonic required
- 600ml
- Estimated final strength
- 10.78%
- Alcohol units
- 2.16
- Ingredient cost
- £2.60 per serve
Buy 1 × 700ml bottle
Buy 1 × 1000ml pack
Assumes tonic is 0% ABV and volumes combine
8.62 UK units across the batch
£10.41 used · £31.50 to buy complete packs
Selected starting point
Tanqueray London Dry
Use the price fields above for a real cost comparison.
Price outputs use only the values you enter; they are not live retailer prices. Left after this batch: about 500ml gin and 400ml tonic. Retail links may earn us a commission without changing your price.
More gin-forward
One part gin to 2.5 parts tonic
Beefeater publishes 50ml gin with 125ml tonic. Use the same cold, measured setup when comparing it with a 1:3 serve.
Change one variable
Measure before adding more gin
If a serve feels weak, reduce tonic by 10–15ml next time. Free-pouring extra gin changes both the ratio and alcohol units.
The arithmetic
What the result means
All price results come from your entries. We do not scrape or invent a live bottle price.
- 1. Shopping quantity: per-serve measures are multiplied by servings, divided by each pack size and rounded up.
- 2. Cost: ingredient cost counts only what is poured; checkout cost counts the complete packs needed.
- 3. Strength and units: estimated final ABV assumes 0% tonic and no ice dilution. Units use gin millilitres × labelled ABV ÷ 1,000.
Sources and limits
Published serves, transparent estimates
The two branded presets reproduce producer-published quantities; they are not taste-test scores. Check the ABV on your bottle. Source and formula check: 20 September 2026.
- Tanqueray — London Dry & Tonic: 50ml gin and 150ml tonic.
- Beefeater — Gin & Tonic: 50ml gin and 125ml tonic.
- NHS — alcohol units: ABV × volume in ml ÷ 1,000.
- GOV.UK — low-risk drinking guidelines.
Gin and tonic questions
What is a good gin-to-tonic ratio?
One part gin to three parts tonic is a practical starting point. Tanqueray publishes 50ml gin with 150ml tonic. Beefeater publishes a slightly stronger 50ml to 125ml serve. Taste and adjust rather than treating either as a universal rule.
How much gin and tonic do I need for ten people?
At 50ml gin and 150ml tonic per serve, ten drinks need 500ml gin and 1.5 litres of tonic. The calculator rounds this up into the bottle and tonic-pack sizes you enter.
How many UK units are in a gin and tonic?
A 25ml measure of 40% ABV gin is 1 UK unit; 50ml is 2 units. Tonic does not remove those units. Enter the exact gin volume and labelled ABV for your drink.
Does more tonic reduce the alcohol units?
No. More alcohol-free tonic lowers the concentration of the finished drink but does not remove alcohol already poured. The gin measure and its ABV determine the units.
Is the calculated final ABV exact?
It is an estimate that assumes the tonic is 0% ABV and the entered liquid volumes combine. Ice dilution lowers the strength further and varies with ice, glass temperature and serving time.