Squash is a fall staple that brings color, fiber, and important micronutrients to your plate — but its vitamin C content varies widely by variety. Butternut squash provides about 21 mg of vitamin C per 100 g raw, while spaghetti squash offers only about 2.1 mg per 100 g. This makes a real difference when you are tracking your daily intake or planning balanced meals.
This calculator lets you choose your squash type, enter your portion in grams, ounces, or cups, and set a daily vitamin C target (the FDA adult Daily Value is 90 mg). It converts your serving to grams, applies the vitamin C density for that squash, and shows both the total milligrams and the percentage of your target. A step-by-step breakdown lets you verify every number.
It is a practical tool for dietitians, fitness enthusiasts, meal planners, and anyone who wants to know exactly how their favorite squash contributes to daily nutrition.
🥒 Squash Variety
⚖️ Amount
🎯 Daily Vitamin C Target
Step-by-Step Guide
Start by selecting the squash variety you are eating from the dropdown menu. The default selection is raw butternut squash, which has the highest vitamin C content among the common varieties listed. If you are using a different type — acorn, zucchini, pumpkin, or spaghetti squash — simply switch the selection and the calculator automatically updates the vitamin C density it uses.
Next, enter the amount you plan to eat. You can type the portion in grams, ounces, or cups and pick the matching unit from the adjacent selector. If you are measuring by cups, remember that cup weights vary by variety: a cup of diced butternut squash weighs about 140 g, while a cup of spaghetti squash weighs closer to 101 g. You can also use the quick-fill buttons below the input to load common portions instantly.
Finally, set your daily vitamin C target. The default of 90 mg matches the FDA Daily Value used on nutrition labels in the United States, but you can adjust it to a personal goal — for example, 75 mg for adult women or 120 mg during pregnancy and lactation. Press Calculate to see your total vitamin C in milligrams, the percentage of your target, a visual progress bar, and a full step-by-step breakdown of the math.
Tip: If you are measuring raw squash, weigh it before cooking. Vitamin C is heat-sensitive and water-soluble, so cooked squash will generally contain less than the raw values used in this calculator. The results are therefore most accurate for raw portions.
Vitamin C Reference Table
The values below are based on USDA FoodData Central data for raw, edible portions of each squash variety. The per-cup weights are approximate because actual density depends on how the squash is cut — diced, cubed, or shredded pieces pack differently into a measuring cup.
| Squash variety | mg vitamin C per 100 g | approx. g per cup |
|---|---|---|
| Butternut | 21.0 | 140 |
| Zucchini (summer) | 17.9 | 124 |
| Acorn | 11.0 | 116 |
| Pumpkin | 9.0 | 116 |
| Spaghetti | 2.1 | 101 |
The spread is striking: a 100 g portion of butternut squash delivers ten times more vitamin C than the same weight of spaghetti squash. That is why choosing the right variety matters for anyone tracking micronutrients closely.
How the Calculation Works
The calculator performs three steps. First, it converts your portion to grams. If you entered ounces, it multiplies by 28.3495 g per ounce. If you entered cups, it multiplies by the approximate gram weight per cup for the selected variety (for example, 140 g for butternut or 116 g for acorn). Gram entries are used as-is.
Second, it applies the vitamin C density using this formula:
Vitamin C (mg) = grams ÷ 100 × mg per 100 g
So a 140 g serving of butternut squash yields 140 ÷ 100 × 21 = 29.4 mg of vitamin C. Third, the calculator divides that result by your daily target and multiplies by 100 to produce the percentage of your target: 29.4 ÷ 90 × 100 = 32.7%. You can verify every number in the breakdown shown beneath the main result.
Example 1: 200 g of raw zucchini. Vitamin C = 200 ÷ 100 × 17.9 = 35.8 mg. Against a 90 mg target, that is about 39.8% of your daily need.
Example 2: 6 oz of raw acorn squash. Convert to grams: 6 × 28.3495 = 170.1 g. Vitamin C = 170.1 ÷ 100 × 11 = 18.7 mg. Against a 90 mg target, that is about 20.8%.
Factors Affecting Accuracy
Vitamin C is one of the most fragile nutrients in the produce aisle. It degrades when exposed to heat, light, and air, and it leaches into cooking water because it is water-soluble. Boiling tends to cause the largest losses, while steaming, roasting, and microwaving with minimal water preserve more of the vitamin. The values in this calculator represent raw squash, so cooked portions may contain noticeably less vitamin C than the estimate shows.
Natural variation also plays a role. The specific variety or cultivar, soil conditions, time of harvest, and how long the squash sat in storage or on a store shelf all affect the final nutrient content. A squash picked fresh from the garden may test higher than one that has been stored for months in a warehouse. For these reasons, treat the result as a solid estimate rather than an exact laboratory measurement.
Note: This tool provides estimates for educational purposes and is not a substitute for professional dietary advice or laboratory analysis. If you have specific medical or nutritional concerns, consult a registered dietitian or healthcare provider.
Frequently Asked Questions
Which squash has the most vitamin C? Among the common varieties in this calculator, butternut squash is the clear winner at about 21 mg per 100 g raw. Zucchini and acorn squash also contribute useful amounts, while pumpkin is moderate and spaghetti squash is very low at only about 2.1 mg per 100 g.
Does cooking destroy vitamin C? Some loss is unavoidable because vitamin C is heat-sensitive and dissolves in water. Boiling causes the greatest losses; steaming or roasting for a short time preserves more. Adding squash to soups or stews keeps some of the vitamin in the liquid, but if you drain the cooking water, the vitamin goes with it.
How much vitamin C do I need each day? The FDA Daily Value shown on nutrition labels is 90 mg, but individual needs vary by age, sex, and life stage. For example, adult women typically need about 75 mg, while people who smoke need extra because smoking increases oxidative stress. The NIH Office of Dietary Supplements publishes detailed recommendations for every age group.
Can I meet my whole vitamin C target with squash? It would take a large portion. A 200 g serving of butternut squash provides about 42 mg — roughly 47% of the 90 mg Daily Value. For a faster boost, pair squash with foods like bell peppers, broccoli, oranges, or strawberries, which are among the richest vitamin C sources.
Additional Resources
For deeper information on vitamin C and how your body uses it, the NIH Office of Dietary Supplements Vitamin C Fact Sheet is an authoritative reference covering recommended intakes, deficiency symptoms, and safety considerations. To look up nutrient values for specific branded or generic foods, search the USDA FoodData Central database, which is the source behind the values used in this calculator.
If you are planning meals around seasonal produce, you can use this calculator together with the same tool for different varieties, or simply compare the reference table above to decide which squash deserves a spot in your next dish.