gin and tonic alcohol content
Here’s the simple way to figure it out, plus ready-made examples.
The formula
Drink ABV (%) = (Gin ABV × Gin volume) ÷ (Gin volume + Tonic volume + Melted ice) × 100
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Treat tonic as 0% ABV.
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Melted ice (water from ice) lowers the final ABV if you include it.
Quick examples (50 ml pour)
| Gin ABV | Ratio (gin : tonic) | Volumes used | Drink ABV (no ice melt counted) |
|---|---|---|---|
| 40% | 1 : 3 | 50 ml gin + 150 ml tonic = 200 ml | 10.0% ( (0.40×50)/200 ) |
| 40% | 1 : 2.5 | 50 ml + 125 ml = 175 ml | 11.4% |
| 40% | 1 : 2 | 50 ml + 100 ml = 150 ml | 13.3% |
| 43.1% (Tanqueray EU) | 1 : 2.5 | 50 ml + 125 ml = 175 ml | 12.3% |
| 47.3% (Tanqueray US) | 1 : 3 | 50 ml + 150 ml = 200 ml | 11.8% |
| 47.3% (Tanqueray US) | 1 : 2 | 50 ml + 100 ml = 150 ml | 15.8% |
| 57% (Navy) | 1 : 3 | 50 ml + 150 ml = 200 ml | 14.3% |
What melted ice does
If that first 40%/1:3 G&T (10.0% ABV) picks up +50 ml of meltwater over time, the total becomes 250 ml → 8.0% ABV. More melt = lower strength.
“Standard drink” equivalents (useful for pacing)
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Pure alcohol in 50 ml of 40% gin: 20 ml ethanol ≈ 15.8 g alcohol.
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≈ 1.13 US standard drinks (14 g)
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≈ 2.0 UK units (8 g)
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Takeaways
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Most classic G&Ts land around 10–13% ABV, depending on gin strength and ratio.
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Higher-ABV gins and shorter tonics push you toward 13–16%; tall, icy serves drift closer to 8–11% as they dilute.
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For a crisp but not too strong G&T, start near 1 : 2.5 (gin : tonic) and adjust to taste.