The Short Answer
So 100 grams of lemon juice is a little under ½ cup, and 122 grams is almost exactly ½ cup. This figure is backed by USDA food composition data, which puts raw lemon juice at a density just slightly above water — around 1.03 grams per milliliter, compared to water's 1.0.
Grams To Cups Converter
Convert grams to cups instantly for common cooking and baking ingredients.
Grams to Cups Chart
| Grams | Cups | Ounces |
|---|---|---|
| 15 g | 1 tbsp | 0.53 oz |
| 31 g | ⅛ cup | 1.09 oz |
| 61 g | ¼ cup | 2.15 oz |
| 81 g | ⅓ cup | 2.86 oz |
| 122 g | ½ cup | 4.30 oz |
| 163 g | ⅔ cup | 5.75 oz |
| 183 g | ¾ cup | 6.46 oz |
| 244 g | 1 cup | 8.61 oz |
| 366 g | 1½ cups | 12.91 oz |
| 488 g | 2 cups | 17.21 oz |
| 732 g | 3 cups | 25.82 oz |
Fresh vs. Bottled: Does the Weight Change?
Not meaningfully. Fresh-squeezed lemon juice and bottled lemon juice (the kind made from concentrate, like ReaLemon) weigh close to the same per cup — both land right around the 240–244 gram mark. Where they genuinely differ is flavor, not weight: fresh juice has a brighter, more layered taste, while bottled juice tends to taste more uniform and slightly cooked, since it's been pasteurized and reconstituted from concentrate.
That difference matters more in some recipes than others. In something like lemon curd or lemon bars, where lemon is the entire point of the dish, fresh juice makes a noticeably better result. In recipes where lemon juice is playing a supporting role — activating baking soda, deglazing a pan, balancing a sauce — bottled juice does the job just fine.
How Many Lemons Do You Actually Need?
This is usually the more useful question than the gram conversion itself. A medium lemon typically yields about 3 tablespoons of juice (roughly 45 mL), which puts the math at:
| Amount Needed | Approx. Lemons (Medium) |
|---|---|
| 1 tablespoon | ½ lemon |
| ¼ cup (4 tbsp) | ~1½ lemons |
| ½ cup | ~2½–3 lemons |
| 1 cup | ~5–6 lemons |
Lemon size and juiciness vary a fair amount, so treat this as a solid starting estimate rather than an exact promise — a smaller, drier lemon might only give you 2 tablespoons, while a large, heavy one can give you 4 or more. If a recipe's success depends on an exact liquid amount, it's worth measuring the juice directly rather than counting lemons and hoping.
Zest Before You Juice
If a recipe calls for both lemon zest and lemon juice, always zest the lemon first. Once a lemon has been juiced, the peel collapses and becomes much harder to grate cleanly against a microplane or zester. A single medium lemon typically yields about 1 tablespoon of zest — enough for most recipes that call for "the zest of one lemon."
The Baking Soda Reaction: A Common Number That's Slightly Off
Lemon juice's acidity (its pH sits around 2, quite acidic) is strong enough to react with baking soda and produce lift in a batter, the same way buttermilk or vinegar does. You'll sometimes see this ratio quoted as "1 teaspoon of baking soda per tablespoon of lemon juice," but that overstates how much baking soda is actually needed. Based on the chemistry of the reaction and how professional bakers test this in practice, the more accurate starting point is:
About ½ teaspoon of baking soda per 1 tablespoon of lemon juice
Using much more than that tends to leave a soapy, slightly metallic aftertaste from unreacted baking soda, since the excess doesn't have enough acid left to react with. If you're adjusting a recipe's acidity and want to neutralize lemon juice's tartness rather than get technical about the ratio, it's easier to add baking soda gradually, stir, and taste as you go rather than trying to hit an exact number.
Getting More Juice Out of a Lemon
A couple of small habits make a real difference in yield:
- Roll the lemon firmly on the counter before cutting it — this breaks down some of the internal membranes and releases more juice once you squeeze.
- Use room-temperature lemons rather than cold ones . A lemon straight from the fridge yields noticeably less juice than one that's been sitting at room temperature; some sources put the difference as high as 20–30%.
- Microwave briefly if a lemon feels firm . A few seconds of gentle heat can loosen the pulp similarly to rolling, especially for lemons that have been refrigerated.
Quick Reference
- 61 g lemon juice = ¼ cup
- 122 g lemon juice = ½ cup
- 244 g lemon juice = 1 cup
- 15 g lemon juice ≈ 1 tablespoon
- 1 medium lemon ≈ 3 tablespoons juice + 1 tablespoon zest
The Bottom Line
Lemon juice converts almost exactly like water — 244 grams to the cup — which makes it one of the simplest liquids on this site to measure. The part worth paying closer attention to isn't the grams-to-cups math; it's knowing how many actual lemons that translates to, and getting the zest off before you juice, since there's no undoing that step once the lemon's been squeezed.
Other Ingredients
Grams-to-cups conversion isn't only useful for lemon juice. Each of these has its own weight-per-cup because densities differ: