G Fuel vs Monster Energy: caffeine compared
Monster Energy (16 oz) has 160 mg of caffeine, 20 mg more than G Fuel (1 scoop, 140 mg) — 1.1× as much per serving.
| G Fuel | Monster Energy | |
|---|---|---|
| Serving | 1 scoop | 16 oz |
| Caffeine per serving | 140 mg | 160 mg |
| Per fl oz | — | 10.0 mg |
| Share of 400 mg/day | 35% | 40% |
| Servings to reach 400 mg | 2.9 | 2.5 |
| Hours until under 50 mg | 7.4 h | 8.4 h |
| Last one for an 11 PM bedtime · standard (50 mg) | 3:34 PM | 2:37 PM |
| Last one for an 11 PM bedtime · sensitive (25 mg) | 10:34 AM | 9:37 AM |
| Share of the 200 mg pregnancy limit | 70% | 80% |
One serving of each, over 16 hours
Common questions
Which has more caffeine, G Fuel or Monster Energy?
Monster Energy (16 oz) has about 160 mg versus 140 mg in G Fuel (1 scoop): 20 mg more, or 1.1× as much.
How many G Fuel servings equal one Monster Energy?
About 1.1 servings of G Fuel (1 scoop) match the caffeine in one Monster Energy (16 oz).
When should I stop drinking G Fuel or Monster Energy before bed?
For an 11 PM bedtime with a 50 mg limit and a 5-hour half-life: last G Fuel by 3:34 PM, last Monster Energy by 2:37 PM. Half-life varies from about 1.5 to 9.5 hours between people.
Method
Caffeine per labeled serving, from the same drink table every calculator here uses (FDA/USDA reference amounts and manufacturer labels; see caffeine content of every drink). Brewed drinks vary batch to batch, so read these as typical values. Decay uses a 5-hour average half-life with a 45-minute absorption ramp; cutoff = bedtime − 5 h × log₂(dose ÷ limit). Percentages use the FDA's 400 mg/day figure for healthy adults and the 200 mg/day limit ACOG gives for pregnancy.
Source — G Fuel: G FUEL FAQ (Energy Formula: 140 mg per serving), checked 2026-10-13.
Source — Monster Energy: CSPI caffeine chart (Monster Energy Original, 16 oz), checked 2026-10-13.