Preparation result
Step-by-step working
Important safety notice
Always follow the product label and safety data sheet. Never mix different disinfectants unless the manufacturer explicitly permits it.
Never mix chlorine bleach with ammonia or acids. Use ventilation, gloves, eye protection, labeled containers, and approved measuring equipment.
Saved preparation records
| Date | Product | Mode | Summary | Action |
|---|---|---|---|---|
| No saved records yet. | ||||
Formula used
Standard dilution: C₁V₁ = C₂V₂
Concentrate required: V₁ = (C₂ × V₂) ÷ C₁
Water required: Vwater = V₂ − V₁
Top-up or under-strength correction: x = Vexisting(Ctarget − Cexisting) ÷ (Cstock − Ctarget)
Over-strength correction: Vfinal = Ccurrent × Vcurrent ÷ Ctarget
Ratio 1:n: concentrate = final volume ÷ (n + 1)
Percent, ppm, mg/L, and g/L conversions assume compatible concentration bases. Confirm weight, volume, density, and label definitions before mixing.
How to use this calculator
- Select the calculation mode matching your preparation task.
- Enter the product label strength and desired working strength.
- Choose matching units and specify the required solution volume.
- Add label limits, contact time, and expiration details.
- Calculate, review warnings, then measure using approved equipment.
- Copy, print, download, share, or save the preparation record.
Concentration and ratio guide
| Format | Meaning | Equivalent example |
|---|---|---|
| 1% | One part per hundred | 10,000 ppm |
| 1 ppm | One part per million | Approximately 1 mg/L in water |
| 1 g/L | One gram per liter | 1,000 mg/L |
| 1:9 | One concentrate plus nine water parts | Ten total parts |
| 1:10 product-to-water | One concentrate plus ten water parts | Eleven total parts |
Example calculations
| Task | Stock | Target | Final volume | Calculated mixture |
|---|---|---|---|---|
| Standard dilution | 5% | 0.5% | 1 L | 100 mL concentrate and 900 mL water |
| PPM dilution | 10,000 ppm | 500 ppm | 2 L | 100 mL concentrate and 1.9 L water |
| Ratio dilution | 1:9 | Not applicable | 5 L | 500 mL concentrate and 4.5 L water |
| Over-strength correction | 1% | 0.5% | 1 L existing | Add 1 L water |
| Batch planner | 5% | 0.5% | 4 × 500 mL | 200 mL concentrate and 1.8 L water |
Examples demonstrate mathematics only. They do not establish safe product concentrations.
Common mistakes and safety checks
- Confusing final volume with water volume causes mixing errors.
- Mixing concentration bases can produce inaccurate conversions.
- Household spoons provide unreliable chemical measurements.
- Ignoring contact time may reduce disinfection effectiveness.
- Unlabeled bottles can cause dangerous accidental use.
- Old prepared solutions may lose their labeled effectiveness.
- Combining bleach, ammonia, or acids can release toxic gases.
Frequently asked questions
1. What formula calculates a disinfectant dilution?
The standard equation is C₁V₁ = C₂V₂. It relates stock strength, stock volume, target strength, and final volume.
2. Does final volume equal added water?
No. Final volume includes both concentrate and water together.
3. Are ppm and mg/L always identical?
They are approximately equal for dilute water-based solutions. Product density and concentration basis can change that relationship.
4. What does a 1:9 ratio mean?
This calculator treats it as one concentrate part plus nine water parts. Some labels define ratios differently, so verify the wording.
5. Can this calculator replace the product label?
No. The label and safety data sheet control approved use.
6. Why must target strength stay below stock strength?
Dilution only reduces concentration. A stronger target requires a stronger source product.
7. How can an over-concentrated batch be corrected?
Add the calculated water quantity when the label permits correction. Mix thoroughly and verify the final concentration.
8. How can an under-concentrated batch be corrected?
Add a calculated amount of stronger stock solution. Confirm adequate container capacity before adding it.
9. Why include measuring loss?
Small quantities may remain inside measuring tools. The loss option increases planned quantities without changing proportions.
10. How should prepared solution be labeled?
Include product, concentration, preparation date, expiration, hazards, and responsible person. Follow workplace and manufacturer requirements.
11. Can prepared disinfectant be stored indefinitely?
No. Stability varies by product, container, temperature, light, and contamination.