Diet Coke has more caffeine than Peace Tea on both counts: 46mg per 12 oz can against 23mg per 23 oz can, and about 4mg per fluid ounce against 1. The serving sizes differ, so the table below shows both ways of counting.
These are different categories of drink, which changes how the caffeine arrives. Energy drinks and sodas list an exact number because caffeine is a measured additive; brewed drinks vary with the beans and the brew, so their figures are compiled averages. The numbers here are the standard published values for each.
Diet Coke vs Peace Tea: the numbers
| Diet Coke | Peace Tea | |
|---|---|---|
| Caffeine per serving | 46mg per 12 oz can | 23mg per 23 oz can |
| Caffeine per fl oz | 3.8mg | 1.0mg |
| Servings to reach 400mg (FDA context) | 8.7 | 17.4 |
Sources: Diet Coke's figure is verified in our Diet Coke caffeine guide against Caffeine Informer (source); Peace Tea's figure is verified in our Peace Tea guide against Caffeine Informer (source).
The concentration gap is the striking part: Diet Coke packs roughly 4 times the caffeine per ounce. Sipping speed matters at that density; a 12 oz can finished in minutes hits differently than the same milligrams spread over a slow cup.
Which one should you pick?
Pick Peace Tea when you want the lighter dose or a slower ramp, and Diet Coke when you actually need the bigger hit and know your tolerance. If you are stacking either with other caffeinated drinks through the day, run the math against the 400mg reference rather than guessing.
For context, the FDA cites 400mg of caffeine a day as an amount generally not associated with negative effects in healthy adults. Tolerance and health vary, so treat these numbers as information, not advice.
Related reading
- Diet Coke: the full caffeine guide
- Peace Tea: the full caffeine guide
- The verified caffeine database
- Every drink compared: the comparisons index
FAQ
Does Diet Coke or Peace Tea have more caffeine? Diet Coke: 46mg per 12 oz can versus 23mg per 23 oz can for Peace Tea.
Which is stronger per ounce? Diet Coke, at about 3.8mg per fluid ounce versus 1.0mg for Peace Tea.
Comparing caffeine? The caffeine comparison tool puts hundreds of drinks side by side, and the caffeine curfew calculator can check your cutoff time for tonight.