Dilution Calculator
Work out how much stock solution and diluent you need with C1V1 = C2V2, mix concentrates at any 1:X ratio, plan a serial dilution, and solve the density and half-life formulas.
Dilution calculator (C1V1 = C2V2)
Mix ratio (1:X) for sprays and cleaners
Serial dilution
Density formula and half life formula
How the dilution calculator works
The amount of solute stays the same when you add solvent, so C1 × V1 = C2 × V2. To make 500 mL of 0.5 M from a 10 M stock: V1 = 0.5 × 500 ÷ 10 = 25 mL of stock plus 475 mL of water (a 1:20 dilution). Units only need to match on each side: M with M, % with %, mg/mL with mg/mL. Add acid to water, not water to acid.
Mix ratios
A 1:32 ratio means 1 part concentrate to 32 parts water, 33 parts total. For a gallon (128 oz): 128 ÷ 33 = 3.88 oz of concentrate and 124.1 oz of water. Product labels sometimes mean "1 part in 32 total"; check the label.
Density formula
ρ = m ÷ V. 54 g in 20 cm³ is 2.7 g/cm³, the density of aluminum. Water is 1.000 g/cm³ (62.4 lb/ft³) at 4 °C.
Half life formula
N = N₀ × (1/2)t ÷ t½. Carbon-14 has a half-life of about 5,730 years, so after 10,000 years 29.8% of the original remains. The same formula covers drug elimination (after 5 half-lives about 3% remains) and radioactive decay.
Common questions
How do I calculate a dilution?
C1V1 = C2V2: V1 = C2 × V2 ÷ C1. 0.5 M × 500 mL ÷ 10 M = 25 mL of stock.
What does a 1:10 dilution mean?
Usually 1 part stock in 10 parts total (1 + 9). Check whether your protocol means parts of total or parts added.
How much concentrate for 1:32 in a gallon?
About 3.88 oz of concentrate and 124 oz of water.
What is the density formula?
Density = mass ÷ volume (ρ = m/V).
What is the half-life formula?
N = N₀ × 0.5^(t ÷ half-life).
Sources
Related
General information, not financial, tax or legal advice. Check important numbers with the official source before acting on them.