Lemon vs lime: carbs, fiber and net carbs

On the table, lemon and lime are near twins: per 3.5 oz (100 g), 29 calories in lemon and 30 in lime, and 2.8 g of fiber in each. In the amounts you actually use, pick by taste.

Vitamin C is where you would expect a winner, and the food tables disagree. USDA gives lemon flesh 53 mg per 3.5 oz (100 g) and lime 29.1 mg. The UK table gives lemon 34 mg and lime 46 mg, so the order flips. A lime wedge of 8 g carries about 2 mg.

Both fruits are studied for kidney stones as a treatment, not a squeeze over dinner. In 30 people with calcium stones and low urinary citrate, lemon juice for 3 months raised urinary citrate 2.5-fold, against 3.5-fold for the drug potassium citrate. That trial measured urine, not stones. The lime trials used a lime-based supplement. In 173 people after stone removal, stones came back within two years in 14 percent on it and 45 percent on placebo. A 2026 review found low-strength evidence of more minor side effects with lemon juice.

Lime has one drug caution. With felodipine, a blood pressure drug, quarter-strength lime juice left average drug levels unchanged but more than doubled them in 2 volunteers.

If you have had stones, talk to your urologist before relying on either.

Evidence behind this note

1. Level E The US and UK food tables differ by 36% on vitamin C in lemon flesh, 53 against 34 mg per 3.5 oz (100 g), and neither number carries a sample range because the US record predates the sampled Foundation program. USDA FoodData Central, SR Legacy record 167746, with UK CoFID 2021 (Public Health England, OGL v3.0)
2. Level E British composition data give lime flesh 46 mg vitamin C per 3.5 oz (100 g), 58% more than the 29.1 mg in the USDA record, a gap that reflects different samples and methods. CoFID 2021, Public Health England / OGL v3.0
3. Level E One whole lime of 65 g gives about 19 mg vitamin C and a wedge of 8 g about 2 mg, so a squeeze on a meal adds little vitamin C. USDA FNDDS 2021-2023
4. Level B About 2.9 fl oz (85 ml) of fresh lemon juice a day for 3 months raised urinary citrate 2.5-fold in patients with calcium stones and low urinary citrate, against 3.5-fold for the drug potassium citrate and 0.8-fold for diet advice alone. Urol Res, 2008
5. Level B In a 24-month randomized placebo-controlled trial in 173 Thai patients after calcium oxalate stone removal, a lime-based citrate supplement cut 2-year stone recurrence from 45% to 14% (HR 0.24). PLoS One, 2025
6. Level A The 2026 systematic review of 31 studies on preventing recurrent kidney stones found that lemon juice may cause more minor adverse events, and it names no benefit strong enough to list beside water, diet, thiazides and alkali therapy. Ann Intern Med, 2026
7. Level B In a randomized crossover pharmacokinetic study, quarter-strength lime juice did not change average felodipine levels, but it more than doubled drug exposure in 2 volunteers, and lime juice held 4 times more bergamottin than grapefruit juice. Clin Pharmacol Ther, 2003

Written from the studies and agency guidance we hold for both foods, reviewed by the Bioma editorial system. How we verify.

Read more about these foods

• Lemon: the kidney stone question, and how much juice the trials used
• Lime: what the kidney stone trials actually tested

Rankings and guides

• Carbohydrates: what it does and how much you need
• Fiber: what it does and how much you need
• Which foods are highest in dietary fiber?
• Which foods are highest in carbohydrate?
• Added sugar: what it does and what the evidence shows
• Lemon: full nutrition facts

• Lemon: USDA FoodData Central, Lemons, raw, without peel, FDC ID 167746 · full profile · all forms of lemon
• Lime: USDA FoodData Central, Limes, raw, FDC ID 168155 · all forms of lime

Each food is one USDA entry, chosen as it is usually eaten. Other cuts, brands and preparations differ; the links show them. % DV uses FDA Daily Values for adults. How we verify.