A standard single shot of espresso (1 fl oz or 30 ml) has about 63 mg of caffeine, according to Mayo Clinic figures. A double shot has about 126 mg. USDA data puts a single shot near 65 mg, and Starbucks lists 75 mg per shot.
Your real number can be higher or lower. This guide shows the typical amounts per shot size, explains what changes them, and helps you work out how many shots fit into your day.
Caffeine in Espresso Shots by Size
Caffeine scales with the number of shots. The table uses the 63 mg Mayo Clinic average and the 75 mg Starbucks figure so you can see the typical range.
| Shot size | Liquid volume | Caffeine (63 mg/shot average) | Caffeine (75 mg/shot, Starbucks) |
|---|---|---|---|
| Single | 1 fl oz (30 ml) | ~63 mg | ~75 mg |
| Double (doppio) | 2 fl oz (60 ml) | ~126 mg | ~150 mg |
| Triple | 3 fl oz (90 ml) | ~189 mg | ~225 mg |
| Quad | 4 fl oz (120 ml) | ~252 mg | ~300 mg |
These are estimates. Cafés define a “triple” differently, and most US shops now build drinks on a double. A 12 oz latte with two shots usually has about 126 mg or more, because the milk adds no caffeine.
Why the Number Changes From Shot to Shot
No two shots are exactly alike. Published values vary, and a single shot can land anywhere from roughly 45 mg to over 100 mg. These factors cause most of that spread.
Coffee dose. This matters most. Caffeine comes from the ground coffee, not the water. A double made with 20 g of coffee has more caffeine than one made with 14 g, even if both fill the same cup. Your recipe’s dose is the best clue to your real total.
Bean type. Robusta beans have roughly twice the caffeine of arabica beans. Many traditional Italian blends include some robusta, so a shot from one can be stronger than the averages above. If you want to know more about that difference, see our guide to arabica vs robusta.
Shot length. Caffeine dissolves quickly, so a shorter shot such as a ristretto likely has only a little less caffeine than a regular shot. A longer pull (a lungo) can pull out somewhat more. The change is usually modest.
Roast level. Roast matters less than most people think. Dark roast is not a “weaker” caffeine choice. If you measure by weight, the difference is small. If you measure by scoop, light roast beans are denser, so you may use slightly more coffee.
Decaf. Decaf espresso is close to zero, but not always exactly zero. Mayo Clinic lists decaf espresso at 0–1 mg per shot.
Espresso vs. Brewed Coffee: Concentration vs. Total Caffeine
Espresso is stronger by volume, but you drink far less of it. That is why people often get this wrong.
| Drink | Serving | Typical caffeine | Approx. mg per fl oz |
|---|---|---|---|
| Espresso (single) | 1 fl oz | ~63 mg | ~63 |
| Brewed coffee | 8 fl oz | ~95–96 mg | ~12 |
Per ounce, espresso has about five times more caffeine. Per cup, a regular 8 oz mug of drip coffee has more than one single shot. Once you order a double, the totals are close: 126 mg vs. about 96 mg. A large café coffee can easily exceed both.
How Many Espresso Shots Can You Have in a Day?
The FDA says up to 400 mg of caffeine a day is not generally linked to negative effects in healthy adults. Using the 63 mg average, here is what that looks like.
Remember that this limit counts everything you consume, including tea, soda, energy drinks, and chocolate. Sensitivity also differs a lot between people. If you feel jittery, anxious, or can’t sleep, cut back, even if you are under 400 mg. If you are pregnant, take certain medications, or have a heart or health condition, ask your doctor what limit is right for you.
How to Estimate Caffeine in Your Own Espresso
You can get a closer number than the averages with a few simple steps.
- Find your coffee dose. Check the grams of coffee in your basket, or ask your barista. A typical double uses roughly 18–20 g.
- Check the bean. A 100% arabica blend is closer to the averages. A blend with robusta may be higher.
- Use the shop’s numbers when you can. Chains like Starbucks publish caffeine per shot, which is better than a generic average.
- Count in shots, then double-check the drink. A latte, flat white, or americano is just espresso plus milk or water. Count the shots, not the cup size.
- Add a buffer. If you want to stay safely under a limit, assume the higher range (such as 75 mg per shot) instead of 63 mg.
Frequently Asked Questions
How much caffeine is in a double shot of espresso? About 126 mg using the 63 mg-per-shot average. Some chains list around 150 mg for a double, so expect roughly 125–150 mg.
Does espresso have more caffeine than coffee? Per ounce, yes. Per serving, usually no. One shot has less caffeine than an 8 oz cup of brewed coffee, but a double is close to or above it.
Do darker roasts have more caffeine? Not meaningfully. Roast level changes flavor far more than caffeine. The amount of coffee in your shot and the bean type matter more.
Does a shorter shot have less caffeine? Slightly less, in most cases, because caffeine extracts quickly. A ristretto is not a dependable way to cut caffeine.
Sources to cite in your final post: Mayo Clinic (caffeine content table, 63 mg per 1 oz shot), U.S. FDA (400 mg/day guidance for healthy adults), and USDA FoodData Central (~65 mg per shot).
