Four calculators, one panel.
Pick a mode below — switch concentration units freely between molarity and mass-per-volume, everything recalculates live as you type, and every result shows its formula.
The concentration of the solution you're starting with.
How much of the stock solution you're measuring out.
Must be lower than the stock concentration.
The concentration of the solution you have on hand.
The concentration you want to end up with.
How much total solution you want to end up with.
The concentration of the solution before diluting.
How much stock solution went into the mix.
Total volume after topping up with diluent. Must be at least V₁.
A dilution factor of 10 means the same as a 1:10 dilution, or a 10-fold dilution.
Optional — lets the calculator show exact stock and diluent volumes.
Three inputs to an answer.
No manual required — but here's the entire flow in four moves.
Pick a mode
Dilution for stock + target concentration → final volume. Solve stock volume or Solve concentration for the two reverse cases. Ratio & factor for converting a plain 1:N dilution on its own.
Match your units
Toggle between Molarity and Mass / volume for the concentration fields, then pick whatever volume unit you're working in — mL, L, µL, gallons or fluid ounces all convert automatically.
Enter what you know
Type your numbers in, or tap an example chip to see the calculator in action. Everything recalculates the instant you change a value — no submit button needed.
Read the results
The main answer sits up top in large type, with the diluent volume and dilution factor just below it, and the exact formula with your numbers substituted at the bottom. Copy any result set with one click.
One equation, three ways to use it.
Every mode above rests on the same relationship — solved for a different letter.
Final volume
Multiply the stock concentration by the stock volume, then divide by the target concentration. The diluent to add is V₂ − V₁.
Stock volume
Multiply the target concentration by the desired final volume, then divide by the stock concentration.
Final concentration
Multiply the stock concentration by the stock volume used, then divide by the final total volume.
Questions people actually ask.
The short answers — with the long ones one tap away.
What is the dilution formula, C1V1=C2V2?+
C₁V₁ = C₂V₂ says the amount of solute stays the same before and after dilution. C₁ and V₁ are the concentration and volume of the stock solution; C₂ and V₂ are the concentration and volume after adding diluent. Since the solute amount doesn't change, concentration and volume simply trade off.
How do I calculate how much diluent to add?+
Find the final volume first with V₂ = C₁V₁ ÷ C₂ in the Dilution tab. The diluent to add is simply V₂ minus V₁ — the final volume you need, minus the stock volume you already measured out.
How do I find the stock volume needed for a target concentration?+
Rearrange the formula: V₁ = C₂V₂ ÷ C₁. Enter the stock concentration, the target concentration, and the final volume you want in the Solve stock volume tab to get how much stock to measure out.
How do I calculate the final concentration after a dilution?+
Rearrange the formula: C₂ = C₁V₁ ÷ V₂. Enter the stock concentration, the stock volume used, and the final total volume in the Solve concentration tab to get the resulting concentration.
What is a dilution factor, and how does it relate to a ratio?+
A dilution factor of N means the final concentration is 1/N of the stock concentration — the same thing as a 1:N ratio, or an N-fold dilution. The Ratio & factor tab converts a single N value into the percentage of stock used and the stock/diluent volumes for any target total volume.
Can I use this for percent (%) or mg/mL concentrations, not just molarity?+
Yes — every tab has a toggle above the concentration fields to switch between Molarity (M, mM, µM, nM, pM) and Mass / volume (g/L, mg/mL, µg/mL, mg/L, %, ppm). Keep both concentrations in a calculation on the same family, since converting between molarity and mass concentration needs a molecular weight the calculator doesn't have.
Is this tool free, and where does my data go?+
It's completely free and runs entirely in your browser — nothing you type is uploaded, logged, or sent to any server. No account, no sign-up, no limits.