Keto Electrolytes Calculator
Your daily sodium, potassium, and magnesium targets on keto — plus the fastest fix for keto-flu headaches, fatigue, and cramps.
Personalized for your weight, sweat level, and adaptation stage.
Keto flu is usually electrolytes, not carb withdrawal — replacing sodium is the fastest fix.
CarbMeNot tracks your food from a photo so keto feels effortless — free on iOS & Android.
Best keto electrolyte foods
Whole foods (plus a little extra salt) cover most people's needs:
| Food | Electrolyte | Amount |
|---|---|---|
| Bone broth | 1 cup | ~500 mg sodium |
| Pickle juice | ¼ cup | ~900 mg sodium |
| Avocado | 1 fruit | ~700 mg potassium |
| Spinach (cooked) | 1 cup | ~840 mg potassium |
| Salmon | 6 oz | ~700 mg potassium |
| Pumpkin seeds | 1 oz | ~150 mg magnesium |
| Almonds | 1 oz | ~80 mg magnesium |
| Dark chocolate (85%) | 1 oz | ~65 mg magnesium |
Keto flu timeline: what to expect
- Days 1–3: As carbs drop, insulin falls and your kidneys dump sodium and water. This is when headaches, fatigue, and brain fog usually hit.
- Days 3–5: Symptoms peak, then ease quickly once you replace sodium and fluids. Most people turn the corner here.
- Week 2+: Your body adapts to burning fat for fuel; energy and focus typically return and often improve.
Do you need electrolyte supplements?
Not necessarily. Extra salt plus the foods above covers most people. A sugar-free electrolyte powder or a magnesium supplement can help if you train hard, sweat a lot, or still feel off after a few days. Skip products with added sugar, and if you have kidney, heart, or blood-pressure conditions, check with your doctor before loading sodium.
Sources
- StatPearls — Physiology, Sodium (natriuresis and insulin) — why low-carb diets increase sodium excretion.
- NIH Office of Dietary Supplements — Magnesium
- NIH Office of Dietary Supplements — Potassium — the ~4,700 mg adequate-intake anchor.
- USDA FoodData Central — electrolyte content of the foods listed.
Methodology & sources
Targets reflect commonly cited low-carb electrolyte ranges: sodium 3–5 g, potassium near the ~4,700 mg adequate intake, magnesium 300–500 mg. Needs rise on keto because low insulin increases renal sodium excretion.
Educational only — if you have kidney, heart, or blood-pressure conditions, check with your doctor before increasing sodium or supplementing.
Frequently asked questions
- How many electrolytes do you need on keto?
- Aim for roughly 3,000–5,000 mg of sodium, 3,000–4,700 mg of potassium, and 300–500 mg of magnesium per day on keto — higher than usual because low insulin makes your kidneys flush more sodium (and potassium and magnesium follow it out).
- What is the keto flu and how do I fix it?
- The keto flu — headache, fatigue, brain fog, cramps, and irritability in the first days of keto — is almost always electrolyte loss, not carb withdrawal. The fastest fix is sodium: add 1–2 teaspoons of salt or 2–3 cups of broth a day, drink water, and eat potassium- and magnesium-rich foods.
- Why do you need more salt on keto?
- Cutting carbs lowers insulin, and low insulin signals the kidneys to excrete sodium instead of holding it. That's why low-carb dieters often need noticeably more salt than the standard advice — and why under-salting causes most keto-flu symptoms.
- What are the best keto electrolyte foods?
- Sodium: salt, broth, pickles, olives. Potassium: avocado, spinach, salmon, mushrooms. Magnesium: pumpkin seeds, spinach, dark chocolate, and supplements if needed. Whole foods plus a little extra salt covers most people.
- How long does the keto flu last?
- Usually a few days to a week. Replacing electrolytes — especially sodium — often relieves symptoms within a day or two. If it drags on, check that you're getting enough salt, water, potassium, and magnesium.
Related tools
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