Coca-Cola Caffeine Content: How Much Is in Each Can?

A 12 oz (355 ml) can of Coca‑Cola contains 34 mg of caffeine.

• A 12 oz (355 ml) Diet Coke contains 46 mg of caffeine; Coke Zero (355 ml) contains 34 mg.
• A 330 ml Coca‑Cola can contains 32 mg (≈9.7 mg/100 ml); values vary slightly by can size and formulation.
• For context, a 240 ml drip coffee has 96 mg; cold brew (240 ml) ≈ 200 mg.
• FDA guidance for healthy adults is up to 400 mg/day; pregnant women are advised to limit to about 200 mg/day (authorities: FDA, EFSA, Mayo Clinic).

Caffeine in standard Coca‑Cola

Coca‑Cola's common canned sizes are listed in food databases: a 330 ml can contains 32 mg, while the 12 oz (355 ml) can contains 34 mg (dataset values). That equals ~9–9.7 mg per 100 ml, far lower than coffee or energy drinks. USDA FoodData Central and Coca‑Cola labeling reflect these low single‑serving amounts.

Caffeine in Diet Coke

Diet Coke is formulated with more caffeine per serving: a 355 ml can contains 46 mg (13 mg/100 ml). The higher number comes from the brand formula — diet colas commonly have slightly more caffeine to compensate for flavor differences. For people counting milligrams, one Diet Coke equals roughly half a small brewed coffee.

Caffeine in Coke Zero

Coke Zero (355 ml) is listed at 34 mg, the same as regular 12 oz Coca‑Cola in the dataset. Coke Zero and regular Coca‑Cola are close in mg/100 ml; Diet Coke remains the outlier with a higher concentration.

12 oz (355 ml) can comparison — sodas and common beverages

Below is a quick reference comparing common sodas and coffees on the same page so you can see where Coca‑Cola sits.

Product	Serving	Caffeine (mg)	mg / 100 ml
Coca‑Cola	330 ml	32 mg	9.7 mg/100 ml
Coca‑Cola	355 ml (12 oz)	34 mg	9.6 mg/100 ml
Diet Coke	355 ml (12 oz)	46 mg	13 mg/100 ml
Coke Zero	355 ml (12 oz)	34 mg	9.6 mg/100 ml
Pepsi	355 ml (12 oz)	38 mg	10.7 mg/100 ml
Mountain Dew	355 ml (12 oz)	54 mg	15.2 mg/100 ml
Red Bull	250 ml	80 mg	32 mg/100 ml
Drip coffee	240 ml	96 mg	40 mg/100 ml
Cold brew	240 ml	200 mg	83.3 mg/100 ml

How caffeine declines in your body (half‑life math)

Population‑average caffeine half‑life is about 5.7 hours — caffeine roughly halves every 5.7 hours. That means ~69% remains after 3 hours, ~48% after 6 hours, ~33% after 9 hours and ~23% after 12 hours. The table below shows concrete mg remaining from three real servings.

Time	% remaining	34 mg (Coca‑Cola 355 ml)	46 mg (Diet Coke 355 ml)	200 mg (Cold brew 240 ml)
0 h	100%	34 mg	46 mg	200 mg
3 h	~69%	~24 mg	~32 mg	~139 mg
6 h	~48%	~16 mg	~22 mg	~96 mg
9 h	~33%	~11 mg	~15 mg	~67 mg
12 h	~23%	~8 mg	~11 mg	~47 mg

What affects caffeine in a can of Coke?

Primary drivers are serving size and the product formula. Diet Coke is intentionally higher per 100 ml; Coca‑Cola Classic and Coke Zero use similar caffeine concentrations. Regional bottling can cause tiny differences, and labelling rounding rules mean a few milligrams can vary between batches. For accurate tracking, log serving size and variant — apps such as CoffeeLog can automate totals and day totals.

Health, safety and timing

For healthy adults the FDA and other authorities commonly cite up to 400 mg/day as an upper limit; EFSA and Mayo Clinic publish similar guidance. Pregnant people are advised to limit caffeine to about 200 mg/day. The American Academy of Pediatrics discourages regular caffeine for adolescents. If you feel palpitations, severe anxiety, vomiting, or confusion after large doses, seek medical care.

Mayo Clinic guidance notes caffeine can disrupt sleep; many people avoid caffeine within about 6 hours of bedtime because substantial amounts can remain active in the system.

Track it and reduce surprises

One can of Coca‑Cola is a modest 34 mg (355 ml), but multiple sodas, coffee, energy drinks or pills add up quickly. Use a tracker like CoffeeLog or a food database (USDA FoodData Central) to sum daily intake and compare to the 200–400 mg guidance if you have health considerations. This page is informational only; consult a clinician for personal medical advice.