Spinach is famously low in calories, but exactly how low depends on the form you eat — raw leaves, boiled, frozen, or canned. This calculator converts any weight of spinach into calories per gram, total calories, and calories per 100 g, so you can log your portion accurately whether you are building a salad, adding a cooked side dish, or meal-prepping for the week.
You can enter the amount in grams, ounces, cups, or handfuls, then choose the spinach form that matches your meal. An optional daily calorie target shows the serving as a percentage of your day — a helpful frame for weight management and calorie counting. The clear breakdown shows the exact formula used, so you can verify the numbers and apply the same math to any portion.
This tool is designed for anyone tracking calories, planning balanced meals, or learning how low-energy-density foods fit into a healthy diet.
🥬 Spinach Calories Per Gram Calculator
How to Use This Tool
Weigh your spinach on a digital kitchen scale and enter the amount in the calculator. If you do not have a scale, the calculator accepts ounces, cups of raw or cooked spinach, and handfuls using typical kitchen estimates. Next, choose the form of spinach that matches what you are eating: raw fresh leaves, boiled and drained, cooked frozen, or canned. Frozen and canned spinach have different calorie densities from raw spinach, so this selection changes the per-gram result.
The optional daily calorie target (default 2,000 kcal) puts the serving in context and shows what percentage of a typical day it takes up. The quick-fill buttons below the amount field load common portion sizes in grams. Press Calculate calories to see total calories, calories per gram, calories per 100 g, and a short breakdown of the formula. This is especially useful when you are combining spinach with other ingredients in a meal and want to know exactly how much energy the greens themselves contribute.
Spinach Calories by Form
The values in this calculator come from the USDA FoodData Central reference database for edible spinach without added fat or seasoning. The table below shows the standard values used for each form:
| Form of Spinach | Calories per 100 g | Calories per 30 g |
|---|---|---|
| Raw fresh spinach | 23 kcal | 6.9 kcal |
| Boiled and drained | 23 kcal | 6.9 kcal |
| Frozen, cooked | 34 kcal | 10.2 kcal |
| Canned, drained | 21 kcal | 6.3 kcal |
The calorie differences are modest, but they add up if you eat very large salads or use spinach as a regular side dish. A 100 g serving of raw spinach is about three or four cups of loosely packed leaves, so most salads contain only 20 to 50 kcal of spinach before dressing.
Calculation Method
Every result is based on a simple density conversion. First, the calorie value per 100 g is divided by 100 to get a calories-per-gram figure. Then that figure is multiplied by the serving weight in grams:
Total calories = weight in grams × (calories per 100 g ÷ 100)
For example, raw spinach contains 23 kcal per 100 g, which is 0.23 kcal per gram. A 150 g salad of raw spinach therefore supplies 150 × 0.23 = 34.5 kcal. Boiled spinach has the same calorie density, while cooked frozen spinach is about 0.34 kcal per gram. None of these values include butter, oil, salad dressing, cheese, or other toppings; added fats can multiply the calorie count quickly even though the spinach itself stays low in energy.
Worked Examples
Example 1: A raw handful. You grab about 30 g of raw baby spinach for a sandwich. The calculator converts the handful to grams and uses the raw value: 30 × (23 ÷ 100) = 6.9 kcal. That is only about 0.3% of a 2,000-calorie day, so it is nearly a free food in calorie-counting terms.
Example 2: A cooked side dish. You measure 180 g of cooked frozen spinach as a side. With the frozen-cooked option selected, the result is 180 × (34 ÷ 100) = 61.2 kcal. Add a teaspoon of olive oil and the total jumps to roughly 101 kcal, so the preparation method matters more than the spinach itself.
Tips for Accurate Tracking
Weigh spinach raw before cooking whenever possible, because water loss changes the weight but not the calories. If you log cooked spinach, use a cooked entry instead of a raw one to avoid over- or under-counting. A food scale is the most reliable tool; cup and handful estimates vary with leaf size and how tightly the leaves are packed.
When using frozen spinach, squeeze out excess water after thawing and reweigh. The weight after squeezing is closer to the volume you actually eat, and the calorie value per 100 g becomes more accurate.
Spinach is especially rich in potassium, so if you are tracking micronutrients as well as calories, the Spinach Potassium Calculator is a helpful companion. For a broader look at how a leafy salad affects blood sugar, the Salad Glycemic Load Calculator can also be useful.
Frequently Asked Questions
Does cooking spinach lower its calories? No, cooking itself does not destroy calories. Boiling causes water loss and wilting, but the energy content per 100 g stays about the same for raw and boiled spinach. It is added oil and butter that increase calories.
Is spinach a negative-calorie food? No food is truly negative-calorie. Spinach is simply very low in calories and high in water and fiber, so it can be helpful in calorie-controlled diets. The energy cost of chewing and digesting it is tiny compared with the calories it contains.
Should I weigh spinach raw or cooked? For the most accurate tracking, weigh it in the form you are logging. If a nutrition app lists a raw entry, weigh it raw. If it lists cooked, weigh it cooked. The calculator's form selector matches the common raw, boiled, frozen, and canned entries used by nutrition databases.