Regular tonic water is high in sugar (~8.8–9g net carbs per 100ml). If you’re keto, reserve for rare occasions or swap to sugar-free tonic to avoid derailing ketosis.
Is Tonic Water Keto?
Water

KETO VERDICTLIMIT
Regular tonic water is high in sugar (~8.8–9g net carbs per 100ml). If you’re keto, reserve for rare occasions or swap to sugar-free tonic to avoid derailing ketosis.
- Net carbs (100g)8.8g
- Protein (100g)0g
- Fat (100g)0g
- Keto verdictLimit portions
NUTRITION FACTS
Per 100g (raw)
Net Carbs
8.8g
Total Carbs
9g
Fiber
0g
Protein
0g
Fat
0g
Calories
36
Source: USDA FoodData Central
WHY TO LIMIT IT ON KETO
- High sugar content makes regular consumption problematic
- Best reserved for occasional mixers; prefer sugar-free tonic
- 9g net carbs per 100ml adds up quickly in cocktails
- Sugar-free alternatives are widely available
- Keep portions small to maintain ketosis
- Use seltzer/club soda to dilute carb load
HEALTH BENEFITS
- Contains quinine, which contributes characteristic bitter flavor
- Very low micronutrient contribution; primary concern is added sugar
- Sugar-free versions remove most carb impact
- Flavorful mixer when diluted with sparkling water
- Bitter taste can enhance perceived refreshment
- Well-suited to be replaced with no-sugar alternatives on keto
PREPARATION SUGGESTIONS
GIN AND TONIC (SUGAR-FREE)
Mix 1.5oz gin with sugar-free tonic water and a lime wedge for a keto-friendly cocktail.
VODKA TONIC (SUGAR-FREE)
Combine 1.5oz vodka with sugar-free tonic and fresh herbs.
QUININE WATER SPRITZER
Stretch a small amount of sugar-free tonic with sparkling water for lower carb impact.
HERBAL TONIC
Swap regular tonic for herbal bitters + sparkling water for a better carb profile.
LIGHT TONIC MIXER
If using regular tonic, limit to 0.5–1oz and top with club soda.
RARE OCCASION USE
Reserve regular tonic water for celebrations when your carb allowance permits.