Carb Loading Calculator

Carbohydrate loading tops off the glycogen stored in your muscles and liver before a long endurance event. You raise your carb intake to 8 to 12 g per kilogram of body weight per day during the taper, while training volume drops. The goal is to start the race with full fuel tanks so you delay fatigue. It mainly helps continuous efforts lasting longer than about 90 minutes, such as a marathon, long bike race, or triathlon.

Multiply your body weight in kilograms by your target rate. The evidence-based range is 8 to 12 g/kg/day, so a 70 kg runner needs roughly 560 to 840 g of carbohydrate daily, and most athletes aim near 10 g/kg for events over 90 minutes. This calculator does that math and splits the total across your meals and snacks. One gram of carbohydrate supplies 4 calories, so the daily totals add up fast.

Modern protocols load for 1 to 3 days before the event, during the taper when your training is light. A single day at 10 to 12 g/kg can fill muscle glycogen for many trained athletes, while two to three days adds a margin of safety. There is little benefit to loading earlier than that, since the extra glycogen is not stored indefinitely. Use the loading-days input to spread the plan across your taper.

You will likely see the scale rise by 1 to 2 kg, but most of that is water rather than fat. Your body stores roughly 3 g of water with every gram of glycogen, so a full load pulls in extra fluid. That water actually helps on race day because it supports hydration and is released as you burn glycogen. The gain is temporary and usually drops within a day or two after the event.

Lean on starchy, low-fiber, low-fat foods that are easy to eat in volume, such as rice, pasta, bread, potatoes, oats, bananas, and sports drinks. High-fiber and high-fat meals fill you up before you reach the target and can upset your stomach, so scale those back while loading. Splitting the total into frequent meals and snacks, as this calculator does, keeps each sitting manageable. Practice your loading menu before a key race instead of trying new foods the night before.

No. It is an educational sports-nutrition tool that estimates carbohydrate targets from the standard 8 to 12 g/kg/day range. It does not account for diabetes, kidney disease, medications, or other personal medical factors. Talk with a clinician or registered sports dietitian before making large diet changes, especially if you manage a health condition.