Kale or spinach: which is better?
Per cup, spinach has more vitamin K, folate and vitamin A, and kale has more vitamin C and calcium. Weigh them instead and kale also pulls ahead on fiber, while spinach keeps its lead on vitamin K. Neither one wins outright, so use both.
Kale has the reputation as the healthiest green there is, and spinach is the plain one. Put a cup of each side by side and spinach wins more rows. A big part of the reason is how much a cup of each weighs. Curly chopped kale is mostly air, so a cup holds 21 g of it, and a cup of spinach holds 30 g.
What we’d do
Use spinach as the everyday raw base, since it’s tender, mild and the stronger of the two per cup. Add kale for crunch and vitamin C, chopped fine or rubbed with a little of the dressing so it softens. Better still, mix them in one bowl. Changing greens through the week gets you more of everything than picking a winner.
Asking which is better is like asking which basketball player is better without saying whether you mean points or rebounds. It depends on the stat.
Side by side
| Raw | Spinach, per cup | Kale, per cup | Spinach, per 100 g | Kale, per 100 g |
|---|---|---|---|---|
| Weight | 30 g | 21 g | 100 g | 100 g |
| Calories | 7 | 7 | 23 | 35 |
| Vitamin K | 145 mcg | 82 mcg | 483 mcg | 390 mcg |
| Folate | 58 mcg | 13 mcg | 193 mcg | 62 mcg |
| Vitamin A | 141 mcg | 51 mcg | 470 mcg | 243 mcg |
| Vitamin C | 8.4 mg | 19.6 mg | 28 mg | 93 mg |
| Calcium | 30 mg | 53 mg | 100 mg | 252 mg |
| Fiber | 0.7 g | 0.9 g | 2.2 g | 4.1 g |
From the USDA’s raw spinach and raw kale. Per 100 g values are worked out from the cup weights, except where the USDA prints them. Folate is in mcg of dietary folate equivalents and vitamin A in mcg of retinol activity equivalents.
When the winner flips
Per cup, spinach wins vitamin K, folate and vitamin A, and kale wins vitamin C and calcium. Per 100 g, kale adds fiber to its wins, with almost twice spinach’s, and its lead on vitamin C grows to more than three times. Spinach still has more vitamin K, folate and vitamin A by weight.
In a salad you measure greens by the cup or the handful, so the per-cup column is closer to what you eat. If you blend greens into a smoothie or cook them down, the weight columns matter more.
If you take warfarin, keep the amount of leafy greens steady week to week. A cup of spinach has 145 mcg of vitamin K and a cup of kale 82, so switching between them changes your intake. Talk to your doctor before a big change.
Compare more greens
Our greens comparison lines up spinach, kale, romaine, arugula and iceberg by any nutrient and tells you when the ranking flips between per cup and per 100 g. For the other matchups, see what is the healthiest lettuce.
3 sources
- USDA Standard Reference, spinach, rawnutritionvalue.org
- USDA Standard Reference, kale, rawnutritionvalue.org
- MedlinePlus, Warfarin, US National Library of Medicinemedlineplus.gov
