Can I use this for 3%, 6%, 12%, and 35% peroxide?
Yes. Those are the built-in presets, and the calculator also accepts a custom stock percentage if your label uses a different strength.
Hydrogen Peroxide to Add
83.3
mL
of hydrogen peroxide for a 0.5% working solution in 500 mL total volume using 3% stock.
Add peroxide to water
Use opaque bottles
Label date + strength
Mixture Breakdown
Batch math at a glance
Hydrogen Peroxide
83.3 mL
Water Amount
416.7 mL
Total Solution
500 mL
Dilution Ratio
1:5
Target Strength
0.5%
Stock Strength
3%
Peroxide share of solution
16.67% peroxide
Safety Guidelines
Three rules that matter
- Keep stronger stock under control. Higher concentrations are more reactive and can burn skin or eyes.
- Mix in a clean, non-metal container. Add peroxide to water and avoid contact with dirty containers or reactive metals.
- Store away from light and heat. Use opaque bottles and label the finished batch with the date and strength.
Formula Blueprint
How hydrogen peroxide dilution math works
The calculator uses the same C1V1 = C2V2 dilution identity as other concentration tools. It solves for the peroxide volume needed to reach your target strength, then subtracts that amount from the finished batch to get the water volume.
Core Dilution Equation
C1 x V1 = C2 x V2
C1 is the stock peroxide concentration, V1 is the peroxide volume to add, C2 is the target concentration, and V2 is the total finished solution volume.
Peroxide Volume Solved
V1 = (C2 / C1) x V2
Divide the target concentration by the stock concentration, then multiply by the finished batch size. That gives the exact peroxide amount needed.
Water Volume
Vwater = V2 - V1
The water fills the rest of the batch. Add peroxide to the water, not the other way around, to keep the mix controlled and splash-free.
C1Stock concentration on your peroxide bottle (%)
V1Volume of peroxide to add to the water
C2Target finished concentration (%)
V2Total finished solution volume
Reference Table
Common peroxide dilution presets
| Stock % | Target % | Peroxide / 1 L | Water / 1 L | Dilution Ratio | Common Use |
|---|---|---|---|---|---|
| 3% | 0.5% | 166.7 mL | 833.3 mL | 1:5 | Gentle household mix |
| 3% | 1% | 333.3 mL | 666.7 mL | 1:2 | Light cleaning batch |
| 6% | 1% | 166.7 mL | 833.3 mL | 1:5 | General cleaning mix |
| 12% | 3% | 250.0 mL | 750.0 mL | 1:3 | Stronger cleaning batch |
| 35% | 1% | 28.6 mL | 971.4 mL | 1:34 | High-strength stock dilution |
Pro Tips
Measure carefully
Higher stock peroxide leaves less room for measurement error. Use a graduated cylinder or syringe for small peroxide volumes, especially when working above 12% stock.
Storage
Use dark containers
Peroxide breaks down faster when exposed to light, heat, and metal contamination. Opaque bottles help preserve the finished batch longer.
Labeling
Write the strength on the bottle
Label the finished mix with the stock percentage, target percentage, and mix date so you can identify it later without guessing.
Common Questions
Hydrogen Peroxide Calculator FAQ
Quick answers on stock strength, dilution math, storage, and safe handling of peroxide mixes.
Why does the calculator require the target to be lower than the stock?
Dilution only works when you are reducing concentration. If the target is higher than the stock, the mix is not physically possible without adding a stronger source.
Do I need to use opaque bottles?
Yes. Peroxide degrades faster in light, so opaque or dark containers help protect the finished mix from breaking down too quickly.
Can I mix peroxide with other cleaners?
Not unless the product label specifically allows it. Mixing peroxide with other cleaners can create unsafe reactions or reduce effectiveness.
How does the volume unit selector work?
Choose mL, liters, or gallons for the finished batch size. The calculator converts everything internally to milliliters before solving the dilution math.
What is the safest way to handle strong peroxide?
Use gloves, eye protection, and a clean container. If the stock is above 10%, treat it as a corrosive chemical and measure carefully.
Data Integrity
Formula and source verification
This calculator uses C₁V₁ = C₂V₂ to solve peroxide volume with V₁ = (C₂ / C₁) x V₂, then computes water as V₂ - V₁. Inputs are validated so target strength stays below stock strength, consistent with physical dilution limits.
Verified
Reference basis: Dilution equations are verified against analytical chemistry references; handling and labeling guidance is cross-checked with CDC and OSHA sources. High-strength stock handling notes are included because small measuring errors materially change final concentration.
LibreTexts — Concentration and Dilution
Academic chemistry source validating the C₁V₁ = C₂V₂ identity used for concentration-volume calculations.
LibreTexts ChemistryOSHA — Hazard Communication
Used for safety context around chemical concentration labeling and handling requirements for workplace-aligned usage.
OSHA HazCom StandardCDC/NIOSH — Hydrogen Peroxide
Used to align handling cautions with occupational exposure references for hydrogen peroxide solutions.
NIOSH Pocket GuidePubChem — Hydrogen Peroxide
Chemical reference used to cross-check compound identity and concentration terminology used in page documentation.
PubChem Hydrogen Peroxide