Alligation Calculator

Yes — same math. Use grams instead of mL. To make 100 g of a 5% ointment from 2.5% and 10% stocks: 10 − 5 = 5 parts of the 2.5%, 5 − 2.5 = 2.5 parts of the 10%, 7.5 parts in total. 5/7.5 × 100 = 67 g of 2.5%, and 2.5/7.5 × 100 = 33 g of 10%.

Yes if both stocks are in the same unit. Two stocks at 10 mg/mL and 50 mg/mL blended to make 25 mg/mL works identically — just use the numbers directly. The 'percentage' framing is convention; the math is the same for any pair of strengths in the same unit.

With three stocks there are many possible mixes that hit the same target, so there's no single answer. One way is to fix the amount of one stock first, then solve the other two as a normal two-stock problem. The tool handles the standard two-stock case only.

For weight-in-weight (w/w) percentages, no: weights add up exactly. For volume-in-volume (v/v) mixes such as alcohol and water, the volumes don't add up exactly, because the mixture shrinks slightly. Measure the final volume, or work by weight, when the exact volume matters.