Conclusion: Nicotine itself has zero calories, and vaping is very unlikely to meaningfully change your body weight because of “calories in vapor.” The “vape calories” question mostly comes from PG (propylene glycol) and VG (vegetable glycerin)—the base ingredients in many e-liquids—which can be assigned calories in food-labeling contexts. But inhaling a substance is not the same as eating it, and the research does not give a clean, universal “calories absorbed from vaping” number.

Medical note: This article is for general education and does not replace medical advice. If you have concerns about weight, appetite, diabetes, or nicotine dependence, talk with a qualified clinician.

Quick answers

Do vapes have calories?

E-liquid can have “theoretical calories” because its base ingredients (especially VG) are assigned calories in food-labeling contexts. But vaping is not the same as eating, and there isn’t a reliable “calories absorbed per puff” number that applies to everyone.

Does nicotine have calories?

No. Nicotine is not a macronutrient and does not provide caloric energy.

Does vaping count as “calorie intake”?

For most practical purposes, not in a way that’s comparable to food. The bigger drivers of weight change (when they happen) tend to be appetite, habit shifts, and nicotine’s physiological effects, not calories from vapor.

What do “calories” mean

“Calories” is a nutrition framework built for ingestion and digestion. Food calories assume you swallow something, it’s processed by the GI tract, and then metabolized.

With vaping, people often mix up two different questions:

1. Does the liquid contain potential energy if treated like a food ingredient?
2. Do you actually absorb enough of that energy through inhalation to matter?

Most “vape calories” articles answer #1 and imply #2. A better, more honest approach is to answer both—and label the unknowns.

Does nicotine have calories?

No. Nicotine has zero calories.
So if someone is gaining or losing weight while using nicotine products, it’s not because nicotine “contains calories.” It’s more plausible that the change is linked to appetite, cravings, stress routines, sleep, or nicotine’s effects on energy balance (more on that below).

Where “theoretical vape calories” come from (PG/VG)

Most e-liquids are primarily a blend of:

• VG (vegetable glycerin/glycerol)
• PG (propylene glycol)
• nicotine (optional)
• flavors (small amounts)

VG (glycerin)

In food-labeling contexts, glycerin is often treated as a carbohydrate/sugar alcohol and assigned an energy value of around 4.32 kcal per gram.

PG (propylene glycol)

Some published nutritional statements assign 400 calories per 100g of propylene glycol (i.e., 4 kcal per gram) based on standard nutrition labeling factors.

Important: Those numbers describe energy when the substance is treated like a food ingredient, not an inhaled aerosol.

A transparent upper-bound estimate (and why it overestimates)

If you want a number, the most honest way is to compute an upper bound—a “worst-case” estimate that intentionally overstates reality.

Step A — Convert mL of e-liquid to grams (roughly)

PG and VG have different densities:

• PG is about 1.035–1.040 g/mL (20°C)
• Glycerin is about 1.26 g/mL (specific gravity ~1.26)

So, 1 mL of e-liquid weighs roughly ~1.0 to ~1.3 grams, depending on the blend.

Step B — Multiply by calories per gram (food-labeling context)

• PG: 4 kcal/g
• VG (glycerin): 4.32 kcal/g

A simple upper-bound range per mL

• PG-heavy: ~1.04 g/mL × 4 kcal/g ≈ 4.2 kcal per mL
• VG-heavy: ~1.26 g/mL × 4.32 kcal/g ≈ 5.4 kcal per mL

Upper-bound takeaway: If you treated every mL of e-liquid like something you ate and fully absorbed, it would be roughly ~4–5.5 kcal per mL (depending on PG/VG mix).

Example upper-bound table (again: intentionally exaggerated)

Weekly e-liquid use	Upper-bound calories/week (PG-heavy ~4.2 kcal/mL)	Upper-bound calories/week (VG-heavy ~5.4 kcal/mL)
5 mL/week	~21 kcal	~27 kcal
30 mL/week	~126 kcal	~162 kcal
100 mL/week	~420 kcal	~540 kcal

Why does this overestimate real life

Because vaping is not swallowing. This calculation assumes:

• All liquid is aerosolized into you,
• all of it is “retained,”
• and all retained material becomes usable caloric energy like food.

Reality is messier—and the research doesn’t translate retention into “calories gained.”

How much e-liquid do people actually use?

Usage varies wildly, which is why one-size answers are usually wrong.

In a study of daily exclusive e-cigarette users, e-liquid consumption ranged from 5 to 240 mL/week, with a median of 32.5 mL/week.

That’s exactly why the “upper-bound” method is useful: it lets you show ranges (light vs heavy use) instead of pretending everyone is the same.

Do you absorb what you inhale?

Some studies measure exposure and retention (how much is inhaled and how much is not immediately exhaled).

• A human study of JUUL “Menthol” vaping examined exposure and retention of PG, glycerol, nicotine, and menthol and also tracked exhaled residue accumulation.
• Another well-cited nicotine pharmacokinetics paper reported that about 94% of an inhaled nicotine dose was systemically retained under their study conditions.

Key nuance:
Retention ≠ calories. A substance can be retained (not exhaled immediately) without contributing meaningful usable energy in a way comparable to eating food. At the moment, research doesn’t give a standardized “calories absorbed from vaping” metric across devices, liquids, and user behaviors.

Can vaping burn calories?

Not directly like exercise. The only evidence-based angle is that nicotine can influence energy balance (e.g., appetite and energy expenditure/thermogenesis) in the broader nicotine/smoking literature.

But using nicotine as a weight-control method is not a safe or recommended strategy—and the health tradeoffs are not worth it.

Weight gain: what’s more likely than “vape calories.”

When people worry about weight changes around vaping/nicotine, the more plausible drivers are:

（1） Appetite and snack substitution

Nicotine can affect appetite and feeding behaviors in ways discussed in reviews of nicotine and body weight.

（2） What happens when nicotine stops

After smoking cessation, average weight gain at 12 months is commonly reported around 4–5 kg, with most gain occurring early (though individuals vary a lot).

Even though the literature is about cigarettes, it helps explain why some people associate nicotine changes with weight changes—again, not because nicotine has calories, but because nicotine affects the system.