How much Caffeine is there in Coffee,Tea, Colas & Sodas etc.?

Caffeine is the only drug that is present naturally or added to widely consumed foods. Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug.
By means of comparison, a 7 oz cup of coffee has the following caffeine (mg) amounts, according to Bunker and McWilliams in J. Am. Diet. 74:28-32, 1979:

Coffeine in Coffee
(7oz coffee 7 US fluid ounces ≈ 207 ml)
Drip – 115-175 mg
Brewed – 80-135 mg
Instant – 65-100 mg
Decaf, brewed – 3-4 mg
Decaf, instant – 2-3 mg

Coffeine in Tea:
(12oz tea 12 US fluid ounces = 355 ml)
Tea, iced – 70 mg
Tea, brewed, imported – 60 mg
Tea, brewed, U.S. – 40 mg
Tea, instant – 30 mg

Caffeine in Espresso:
Espresso, Single Shot – 29-100 mg (often around 75 mg)
Espresso, Double Shot (or a ‘Doppio’) – 58-185 mg (often around 150 mg)
Decaf Espresso, Single Shot – about 8 mg
Decaf Espresso, Double Shot (Doppio) – about 16 mg
Nespresso Espresso Capsules – 55-65 mg
Nespresso Lungo Capsules – 77-89 mg

Caffeine in Colas & Sodas:
The caffeine levels listed below are for 8 oz. ≈ 236 ml servings.
Pepsi Max/Diet Pepsi Max – 69 mg
Sunkist Orange – 40 mg
Wild Cherry Pepsi – 38 mg
Pepsi-Cola / Pepsi Twist – 37.5 mg
Mountain Dew / Diet Mountain Dew – 37 mg
Diet Pepsi – 36 mg
Coca Cola Zero – 35 mg
Coca Cola Classic – 34 mg
Tab – 31.2 mg
Diet Coke – 30.4 mg
A&W Creme Soda – 29 mg
Dr. Pepper / Diet Dr. Pepper – 27 mg
7-Up / Sprite / Fanta – 0 mg

Caffeine in Energy Drinks:
AMP (8.4 oz) – 74 mg
Enviga (12 oz) – 100 mg
Full Throttle (16 oz) – 144 mg
Jolt (12 oz) – 71.2 mg
Monster Energy (16 oz) – 160 mg
No Fear (8 oz) – 83 mg
No Name (formerly known as “Cocaine;” 8.4 oz) – 280 mg
Red Bull (8.4 oz) – 80 mg

Caffeine in Chocolate:
Dark Chocolate (1 oz ≈ 29 ml) – 20 mg
Milk Chocolate (1 oz ≈ 29 ml) – 6 mg
Chocolate Milk (8 oz) – 4 mg
White Chocolate (1 oz ≈ 29 ml) – 0 mg

Other data on caffeine:
Generic stay-awake pill 100 mg
Vivarin 200 mg
Cold relief tablet with caffeine 30 mg

The variability in the amount of caffeine in a cup of coffee or tea is relatively large even if prepared by the same person using the same equipment and ingredients day after day.