Dilution Ratio Calculator
Calculate exactly how much concentrate and diluent to mix. Use either ratio-based mixing (like 1:10) or the C1V1 concentration formula.
1) Ratio-Based Mixing
Example: A 1:10 ratio means 1 part concentrate + 10 parts water (11 parts total).
2) C1V1 Concentration Method
Use when you know stock concentration (C1), target concentration (C2), and final volume (V2). Formula: C1 × V1 = C2 × V2.
What is a dilution ratio?
A dilution ratio tells you how many parts of concentrate to combine with how many parts of diluent (usually water). If a label says 1:10, that means 1 part concentrate and 10 parts water, for 11 total parts in your finished mix.
This matters for cleaning products, lab solutions, nutrients, disinfectants, and chemical processing. Too strong can damage surfaces or equipment. Too weak may not perform as intended.
Two ways to calculate dilution
1) Ratio parts method
Use this method when instructions are written as ratios like 1:4, 1:10, or 2:3.
- Add both parts together to get total parts.
- Concentrate volume = Total volume × (concentrate parts ÷ total parts).
- Diluent volume = Total volume × (diluent parts ÷ total parts).
Example: For a 1:10 mix with 1100 mL total volume, use 100 mL concentrate and 1000 mL water.
2) C1V1 concentration method
Use this method when concentrations are known (for example % or ppm). You can solve for how much stock solution to use:
V1 = (C2 × V2) ÷ C1
- C1 = concentration of stock solution
- C2 = desired final concentration
- V2 = final total volume
- V1 = required stock volume
Then the amount of diluent is simply V2 − V1.
Common dilution examples
Cleaning spray concentrate
If the bottle says 1:20 and you want 500 mL ready-to-use spray:
- Total parts = 21
- Concentrate = 500 × (1/21) = 23.81 mL
- Water = 500 × (20/21) = 476.19 mL
Lab prep with C1V1
You have a 40% stock and need 2% final concentration, total 250 mL:
- V1 = (2 × 250) ÷ 40 = 12.5 mL stock
- Diluent = 250 − 12.5 = 237.5 mL
Best practices for accurate dilution
- Use consistent units throughout your calculation.
- Measure with accurate tools (graduated cylinder, syringe, pipette).
- Add concentrate first when instructions require it.
- Mix thoroughly before use.
- Label containers with concentration and date.
- Always follow manufacturer safety guidance and PPE requirements.
Quick unit reminders
- 1000 mL = 1 L
- 128 fl oz = 1 US gallon
- 1 cup = 8 fl oz
FAQ
Does 1:10 mean 10 parts total?
No. It means 1 part concentrate plus 10 parts diluent, so 11 total parts.
Can target concentration be higher than stock concentration?
No. Dilution only makes a solution weaker. If C2 is greater than C1, you cannot reach that target by adding diluent.
Can I use this for percent and ppm?
Yes—if both concentrations use the same unit basis (for example, both in % or both in ppm), the C1V1 method works.