Dilution Ratio Calculator
Enter exactly any two fields, then click Calculate. Ratio is Water : Concentrate = r : 1.
Results
Final volume
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Concentrate
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Water
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Ratio
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Step-by-step derivation
Quick summary
References
- Total parts = 1 concentrate + r water, so V = S + W and W = r × S.
- Useful formulas: S = V / (r + 1) and W = r × V / (r + 1).
- 1 L = 1000 mL.
Use this Dilution Ratio Calculator to calculate how much water and concentrate are needed for a mixture. The calculator uses the ratio format Water : Concentrate = r : 1.
Dilution Ratio Formulas
For a ratio of r : 1:
Total parts = r + 1
Concentrate = final volume ÷ (r + 1)
Water = final volume × r ÷ (r + 1)
If water and concentrate are already known:
Ratio = water volume ÷ concentrate volume
The final mixture volume is:
Final volume = water + concentrate
Example
Suppose you need 5 litres of solution at a 4:1 water-to-concentrate ratio.
Total parts = 4 + 1 = 5
Concentrate = 5 ÷ 5 = 1 L
Water = 5 × 4 ÷ 5 = 4 L
You therefore need 4 litres of water and 1 litre of concentrate.
Important Notes
- In this calculator, 4:1 means 4 parts water to 1 part concentrate. Some product labels may write ratios in a different order.
- Use compatible volume units when entering values.
- The calculation assumes that water and concentrate volumes add directly.
- This calculator performs volume-ratio math only. It does not calculate molarity, ppm, active-ingredient concentration, density, or chemical reactions.
- For cleaners, disinfectants, pesticides, laboratory chemicals, or other concentrates, always follow the product label or Safety Data Sheet instead of relying only on a generic ratio calculation.
- Never mix chemicals unless the product instructions specifically state that the mixture is safe.