A walkthrough, end to end.
- 1
Enter your TDEE (or weight + activity for an estimate) and pick a carb strategy.
- 2
Carbs make up your remaining kcal after protein and fat are set; this calculator gives a g/day from a percentage or g/kg target.
- 3
See timing guidance — most performance benefit comes from carbs around training, not arbitrary daily totals.
Carb targets
ISSN/ACSM endurance guidance: 5–7 g/kg/day (moderate training), 6–10 (intense), 8–12 (ultra/multi-day). Strength training: 4–7 g/kg. Low-carb: <130 g/day. Keto: <50 g/day.
What you can do with this.
Carbs for endurance training
Marathoners and cyclists in heavy training need 6–10 g/kg/day. Glycogen stores last ~90–120 min of moderate–high intensity; carbs replace what training depletes.
Carbs for strength training
4–6 g/kg/day works for most lifters. Higher carbs improve workout volume and recovery; very low carb during heavy hypertrophy work tends to limit performance.
Low-carb and keto
Low-carb (<130 g/day) suits some metabolic-health goals. Keto (<50 g/day) shifts you to ketosis after 2–4 weeks; performance often dips for the first few weeks during keto-adaptation.
Carb cycling for body recomp
Higher carbs on training days (5–6 g/kg), lower on rest days (2–3 g/kg). Total weekly carbs end up moderate but performance and recovery cluster around training when it matters most.
Carbs during long runs and rides
30–60 g/hour for sessions over 90 min; up to 90 g/hour with multiple-source carbs (glucose + fructose). Train your gut for high intake — it's a learned skill, not innate.
Pre-race carb loading
10–12 g/kg/day for 1–3 days before a marathon or long event. Top off glycogen without weight gain by reducing fiber and fat. The classic 'pasta dinner' is folk wisdom for this protocol.
Carbs for diabetes management
Type-2 diabetes management often benefits from moderate-low carb (40–45% of kcal). Type 1 requires carb counting for insulin dosing — work with your CDE, not a calculator alone.
Carbs for weight loss
Total calories drive weight loss; carb level affects adherence and hunger. Some find moderate carbs (40% kcal) easiest; others thrive on low (<20%). The 'best' macro split is the one you can sustain.
Carbohydrate calculator 2026 — what's current
Continuous glucose monitoring (CGM) data shows individual carb tolerance varies more than expected — same banana spikes one person to 180 mg/dL and another to 110. Use the calculator as a starting target; adjust by how you feel and perform.
Frequently asked.
No — they're the body's preferred fuel for high-intensity exercise. Quality matters: minimally processed sources (whole grains, fruit, legumes, root vegetables) are vastly better than refined sugar and processed snacks.
<50 g/day puts most people in ketosis. Long-term keto is generally safe for healthy adults but may underperform for high-volume endurance work.
For sessions over ~60–90 minutes or twice-daily training, yes — they improve performance and recovery. For shorter sessions, daily total matters more than timing.
Fiber is technically a carb but isn't fully digested — most macro tracking subtracts fiber to get 'net carbs'. Keto specifically counts net carbs; otherwise total carbs is fine.
No. Body composition responds to total daily intake, not timing. Carbs at night may actually help sleep quality for some people; eat them when they suit your schedule and hunger.
No. Calculations run entirely in your browser. Nothing is sent to a server, no analytics on inputs, no cookies.