How Many Calories Are In Captain Morgan 100 Proof? | Shot-By-Shot Facts

What “100-Proof” Means For Calories

Proof is just double the alcohol by volume. So a 100-proof bottle sits at 50% ABV. All the energy comes from ethanol at about 7 calories per gram, not from sugar or fat. That’s why plain rum brings nearly zero carbs. The higher the proof, the more grams of alcohol you’re drinking in the same pour, and the higher the calorie count climbs.

To translate that into everyday pours, here’s a quick view that covers common sizes you’ll meet at home and behind the bar.

Calories By Common Pour Size

Serving	Alcohol (g)	Calories (kcal)
1.0 fl oz (bartender’s “short”)	~11.7 g	~82
1.25 fl oz (many home jiggers)	~14.6 g	~103
1.5 fl oz (standard shot)	~17.5 g	~123
2.0 fl oz (generous pour)	~23.3 g	~163

Set your pour size first, and the rest is easy. Snacks and late-night bites fit better once you set your daily calorie needs. Then a rum pour can slot in without guesswork.

Why Captain Morgan 100-Proof Lands Around 123 Calories Per Shot

The math is straightforward. A 1.5-ounce shot equals 44.36 mL. At 50% ABV, that shot holds about 22.18 mL of ethanol. Ethanol’s density is ~0.789 g/mL, so you’re drinking roughly 17.5 grams of alcohol. Multiply by 7 calories per gram and you land near 123 calories. That’s the energy in a neat pour before any mixer touches the glass.

If you’re thinking in “standard drinks,” a U.S. standard is 14 grams of pure alcohol. A 100-proof 1.5-ounce shot is a tick above that mark. You’ll see the 14-gram baseline explained by the National Institute on Alcohol Abuse and Alcoholism’s page on the standard drink, which helps compare pours across beer, wine, and spirits.

Does Spice Change The Count?

With unflavored rum, calories track almost entirely with alcohol. Spiced versions bring botanicals and natural flavors. In this bottle, sugar isn’t meaningfully added in the pour. That’s why carbs stay near zero and the calorie line still follows ABV. If you switch to sweet liqueurs or cream styles, that rule breaks and the count jumps fast.

Shot, Neat, Or On The Rocks

You’ll get the same calories from a neat shot or the same volume over ice. Dilution from melting ice stretches the drink but doesn’t add energy. If you sip slower with rocks, your total stays the same for that serving size.

How Mixers Change The Total

Mixers decide whether your glass stays near a one-hundred-twenty-calorie range or doubles. Zero-calorie seltzer keeps the baseline. Regular cola, ginger beer, and fruit juice add a chunk. If you pour more than a splash, the mixer becomes the main source of calories, not the spirit.

Simple Mixer Math

Think of it as two pieces: spirit calories + mixer calories. A standard shot of this 100-proof rum contributes ~123 kcal. From there, tack on the mixer’s label value. The CDC’s page on standard drink sizes is handy for sizing your pour before you add anything to it, so your math lines up with real-world glasses.

Estimated Calories For Popular Highball Builds

Drink (1.5 oz rum + mixer)	Mixer Calories	Total (kcal)
Rum & Club Soda (8–12 oz)	~0	~123
Rum & Diet Cola (12 oz)	~0–5	~123–128
Rum & Cola (12 oz)	~140	~263
Rum & Ginger Beer (6 oz)	~80	~203
Rum & Orange Juice (8 oz)	~110–115	~233–238

Quick Reference: Ounce-By-Ounce

Need a fast estimate while pouring at home? Use ~82 kcal per fluid ounce for this strength. A 2-ounce old fashioned-style pour will sit near ~164 kcal before any sugar or garnish. A spritz that uses just 1 ounce drops to ~82 kcal.

How To Estimate Any Strength

Here’s a simple formula to apply to any ABV. It also helps you compare an 80-proof bottle with 100-proof at the same pour size.

The Handy Formula

Calories ≈ Volume (mL) × ABV × 0.789 g/mL × 7 kcal/g

For a 1.5-ounce pour at 50% ABV: 44.36 × 0.50 × 0.789 × 7 ≈ 123 kcal. If you swap in 40% ABV, you’ll land near 97 kcal for the same volume. That’s why proof and calories move together.

Carbs, Sugar, And Keto Concerns

Plain rum doesn’t carry sugar into the glass; fermentation and distillation remove it. That’s why carbs read near zero for straight pours. Sweet mixers are where grams add up. If you’re tracking macros, stick to seltzer, diet mixers, or citrus wedges. The spirit’s energy still counts toward your day even without carbs, since those ~7 calories per gram of alcohol still contribute to intake.

Real-World Pours At Home Vs. Bars

Bar shots are usually 1.5 ounces, though some venues pour a touch more. Home jiggers vary: many include a 1-ounce side and a 1.5-ounce side; some cocktail jiggers add a 2-ounce line. If your glassware hides pour size, measure once and write the number down. Then you can repeat it without second-guessing.

Cutting Calories Without Losing The Rum Character

Pick Mixers That Don’t Steal The Show

Club soda, diet cola, or plenty of ice keep the core spice notes up front while holding the total near the baseline. Fresh lime or orange peel adds aroma without extra energy.

Right-Size The Pour

Try a 1-ounce nip in a tall glass with seltzer and citrus. You’ll get the same flavor cues with ~82 kcal instead of ~123.

Build Slow Sippers

Add a big ice cube to slow dilution and stretch the drink. Pace and perception matter. When you sip slower, a smaller pour still feels like a treat.

Safety And Serving Clarity

Labels won’t always list calories on spirits. That’s normal, since alcohol falls outside standard food labeling rules. For planning, use the math above and the NIAAA Alcohol Calorie Calculator to cross-check your totals by week.

FAQ-Style Clarifications (No FAQs Section)

Is A Double Just Double The Calories?

Yes—if you pour 3 ounces at this strength, expect roughly ~246 kcal before mixers. The only time that changes is when you choose lower-proof bottles or split the pour across drinks.

Do Flavored Sodas And Syrups Matter More Than Proof?

Often, yes. A single 12-ounce cola can add more calories than the spirit. Proof matters for the baseline; mixers decide the finish line.

Practical Serving Ideas Under ~150 Calories

Highball With Citrus

Pour 1 ounce in a tall glass, pack with ice, top with club soda, and squeeze a lime wedge. Expect ~82 kcal. Aroma carries the spice so it still tastes complete.

Diet-Cola Splash

Use a 1.5-ounce pour with plenty of ice and a diet-cola top. You’ll sit near ~123–128 kcal depending on brand carbonation and any flavor enhancers.

Short Orange Twist

Stir 1 ounce over ice with an orange peel and a few drops of bitters if you like spice complexity. Keep it small, keep it bright.

Your Next Step

Want a deeper walkthrough of energy budgeting? Try our calories and weight loss guide for a bigger picture on balancing treats with daily intake.