Fresh lime juice

One US cup of fresh lime juice weighs 242 grams (8.5 ounces). Going the other way, 100 grams is about 0.41 cups.

Citrus juices compared: cup weights side by side, the source behind each, and why they differ.

Fruit juices compared: cup weights side by side, the source behind each, and why they differ.

Fresh-squeezed lime juice weighs 242 g per US cup — USDA and every reference source converge exactly on this figure. Density 1.023 g/mL, marginally lighter than lemon juice (244 g/cup) because limes have slightly lower citric acid concentration and lower sugar content.

Fresh lime juice is the acidic liquid squeezed from limes (Citrus aurantifolia, the Key or Mexican lime; or Citrus latifolia, the Persian or Bearss lime dominant in US retail). Composition is roughly 6-8% citric acid by weight, plus small amounts of sugars and vitamin C. Similar to lemon juice with slightly less citric acid on average.

USDA SR Legacy "Lime juice, raw" (FDC 168156) publishes 256 g per metric cup = 242 g per US cup, density 1.023 g/mL. This figure is repeated by every USDA-derived aggregator (aqua-calc, Cups & Grams, medindia, RecipeTips, myfooddata) without variance. ChefSolver's measured density near 1.02 g/mL corresponds to 241 g/cup, matching within 0.5%.

Producer bottled lime juices (Nellie & Joe's Key West, ReaLime, Santa Cruz Organic) cluster near the USDA density since bottled products are reconstituted or preserved to match fresh composition. Density differences between fresh lime, bottled Key lime, and standard bottled Persian lime juice are within measurement variance (all near 240-245 g/cup).

King Arthur's ingredient weight chart has no row for fresh lime juice. It lists bottled "Key Lime Juice" at 1 cup = 8 oz = 227 g, which is lighter than water and is King Arthur's fluid-ounce pattern, eight fluid ounces read as eight weight ounces; it is a bottled product, so it is not used as a source here, but it is wrong for the same reason as King Arthur's lemon juice figure. King Arthur also lists "Lime Juice Powder" at 2 tbsp = 5/8 oz = 18 g, the dehydrated form.

For validation and internal consistency, this entry publishes 242 g per US cup as a high-confidence single figure. USDA and multi-source convergence within 1% supports this position.

Density is slightly above water because fresh lime juice contains dissolved citric acid (6-8% by weight), traces of sugars (0.5-1.5%, less than lemon juice), and other soluble solids. Pure water at 20°C is 0.998 g/mL; lime juice at 1.023 g/mL is about 2.5% denser. The marginal difference from lemon juice (244 g/cup) reflects limes' slightly lower citric acid concentration and lower sugar content — physiologically real but too small to matter in most kitchen contexts.

Practical guidance: for margaritas (fresh lime juice is essential — bottled shifts the flavor profile significantly toward preservative notes), Key lime pie, guacamole, ceviche, and mojitos, weigh lime juice for consistency. A single Persian lime yields 30-45 g of juice; a Key lime yields only 5-15 g due to the smaller fruit size. A cup of fresh lime juice requires roughly 6-8 Persian limes or 20-30 Key limes. Bar-standard 3/4 oz jigger of lime juice weighs about 22 g.

The tablespoon figure (15 g) matches water's 15 g/tbsp within 3% — small quantities of lime juice can be treated as equivalent to water by volume for most applications. For classic sour cocktails (margarita, daiquiri, gimlet) built around a specific citric acid ratio, weighing produces more consistent results than pouring by shot.

Bottled Key lime juice (Nellie & Joe's is the reference brand) has essentially the same density as fresh Persian lime juice — the "Key" designation refers to the botanical variety and flavor profile, not a density distinction. For baking Key lime pie, the difference between bottled Key lime and fresh Persian lime is entirely a flavor decision, not a proportional one.

Companion citrus entry: fresh-lemon-juice at 244 g/cup (marginally denser). Vanilla-extract, another common recipe liquid, is much lighter at ~208 g/cup due to alcohol content.