Carb loading calculator

For events longer than about 90 minutes, eat 10 to 12 g of carbohydrate per kg of body weight per day for the 36 to 48 hours before. For a 75 kg athlete at 10 g/kg that is 750 g a day, which is far more than most people expect. The calculator splits it into meals and snacks with real food examples.

Calculator

Body weight

Target

Loading time

Event length

Hours:minutes

Carbs per day

750g

1,500 g over 48 hours

2 days before

Meal	Carbs
Breakfast	150 g
Lunch	150 g
Dinner	150 g
3 snacks	about 100 g each

1 day before

Meal	Carbs
Breakfast	150 g
Lunch	150 g
Dinner	150 g
3 snacks	about 100 g each

Food	Carbs
Dry pasta, 100 g (cooked weight about 250 g)	72 g
White rice, cooked, 200 g	56 g
Bagel	50 g
White bread, 2 slices	30 g
Banana	25 g
Fruit juice, 250 mL	25 g
Sports drink, 500 mL	35 g
Rice cakes, 4	30 g
Jam or honey, 1 tbsp	13 g
Porridge oats, 80 g dry	48 g

Choose low-fibre foods: white bread, white rice, pasta.
Keep fat low so there is room for the carbs.
Keep eating carbs until the evening before.
Expect 1 to 2 kg of weight gain: that is stored water.

ACSM, Academy of Nutrition and Dietetics and Dietitians of Canada (2016): 10–12 g/kg per 24 h for 36–48 h before events over 90 minutes.

How the carb loading calculator works

Your muscles store carbohydrate as glycogen, the fuel you burn fastest in hard and long efforts. Carb loading means eating much more carbohydrate than usual for a day or two before an event, so you start with full stores. The joint position of the ACSM, the Academy of Nutrition and Dietetics and Dietitians of Canada recommends 10 to 12 g of carbohydrate per kg of body weight per 24 hours, for 36 to 48 hours before events longer than 90 minutes. This tool is one of the free LeCoach cycling calculators.

The calculator multiplies your weight by the target you choose, rounds to 10 g and splits the day into three meals of 20 % each and three snacks that share the other 40 %. For events under 90 minutes it tells you that you do not need to load: a normal carb-rich meal the evening before and a good breakfast are enough.

Worked example. You weigh 75 kg, choose 10 g/kg and load for 48 hours before a 3:30 event. You need 75 × 10 = 750 g of carbohydrate a day, or 1,500 g over the two days. That is about 150 g at breakfast, lunch and dinner, plus three snacks of about 100 g. Over 36 hours instead, the total is about 1,130 g.

Carbs per day by body weight

Body weight	8 g/kg	10 g/kg	12 g/kg
60 kg	480 g	600 g	720 g
70 kg	560 g	700 g	840 g
80 kg	640 g	800 g	960 g
90 kg	720 g	900 g	1,080 g

The 10 and 12 g/kg columns match the guideline. The 8 g/kg option is a lighter choice for athletes who find the full amount hard to eat; it sits below the guideline range, so it gives you less than a full load.

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What a 750 g day looks like

Most people are surprised by how much food this is. Here is one way to reach 750 g, using the values from the food table in the calculator.

Meal	Food	Carbs
Breakfast	Porridge oats 80 g dry, a banana, 2 tbsp honey, fruit juice 250 mL, 2 slices white bread	154 g
Mid-morning	4 rice cakes with 1 tbsp jam, a banana, sports drink 500 mL	103 g
Lunch	White rice, cooked, 400 g, 2 slices white bread with 1 tbsp jam	155 g
Afternoon	A bagel with 2 tbsp jam, a banana	101 g
Dinner	Pasta, 200 g dry weight	144 g
Evening	4 rice cakes with 1 tbsp honey, a banana, fruit juice 250 mL	93 g
Total		750 g

Add some lean protein and a little sauce to the main meals, but keep fat and fibre low. Repeat a similar day for the second day.

How to make carb loading work

Choose low-fibre foods. White bread, white rice, pasta, rice cakes and juice are easier on your gut than wholegrain versions.
Keep fat low. Fat fills you up without adding carbohydrate.
Spread it out. Eat until the evening before the event, not one huge meal at the end.
Expect to gain 1 to 2 kg. Glycogen is stored with water. It is fuel, not fat, and it is a sign the loading worked.
Keep training light. Loading works best during your taper, when you are not burning the stores again. Read more about tapering for cycling events.
Practise before a big training day. Try a loading day before a long ride first, so you know which foods sit well.
Talk to your doctor first if you have diabetes or another condition that affects how you handle carbohydrate.

Common mistakes

One big pasta dinner the night before. On its own it falls far short of 10 g/kg a day for 36 to 48 hours, and it can leave you feeling heavy.
Eating "healthy" high-fibre food. Large amounts of bran, beans and vegetables can upset your stomach on race morning.
Loading for short events. Under 90 minutes, your normal stores are enough.
New foods. Race week is not the time to experiment.
Forgetting race-day fuel. Loading fills the tank before the start. You still need breakfast and carbs during the event. Use the race nutrition calculator to plan them, and read race fueling for cyclists.

For runners, the marathon pace calculator helps you plan the race you are loading for. LeCoach plans your taper and race week around your event date, so the carbs you load go into fresh legs.

Sources

Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine joint position statement: nutrition and athletic performance. Medicine and Science in Sports and Exercise, 2016;48(3):543-568.

Frequently asked questions

How many carbs should I eat when carb loading?

Eat 10 to 12 g of carbohydrate per kg of body weight per day for 36 to 48 hours before an event longer than 90 minutes. For a 75 kg athlete at 10 g/kg, that is 750 g a day, or 1,500 g over 48 hours. Spread it over three meals and three snacks rather than one big meal.

How long before a race should I carb load?

Start 36 to 48 hours before the event, so for a Sunday morning race, begin on Friday morning or midday. Keep eating carbohydrate-rich meals and snacks until the evening before, then have a familiar carb-rich breakfast on race morning. Keep training light during these days so you do not use up the stores.

Do I need to carb load for a short race?

No. For events under about 90 minutes, your normal glycogen stores are enough. A normal carb-rich meal the evening before and a good breakfast on race morning will do. Carb loading starts to pay off for longer events such as marathons, gran fondos and long triathlons.

Why do I gain weight when carb loading?

Your body stores glycogen with water, so a full load usually adds 1 to 2 kg on the scale. That is stored fuel and water, not fat, and it is a sign the loading has worked. You will use it during the event. Do not try to avoid the weight gain by eating less.

What are the best foods for carb loading?

Foods that are high in carbohydrate and low in fibre and fat work best. Good choices are white pasta, white rice, bagels, white bread, rice cakes, porridge, bananas, fruit juice, jam, honey and sports drinks. Choose foods you know your stomach handles well, and avoid large portions of beans, bran and vegetables.

Is 8 g/kg enough for carb loading?

It is below the 10 to 12 g/kg guideline, so it gives you less than a full load. It can be a sensible option if you struggle to eat the full amount, or for a first try at loading. For your main event, aim for at least 10 g/kg if you can eat it comfortably.