Volume Percent (v/v) Calculator

Precision (decimals)

Units convert automatically. Results assume additive volumes and ambient conditions.

Definition: w/v% = grams solute per 100 mL solution. So grams = w/v% × total(mL) ÷ 100.

Calculation log

exportable

#	Time	Mode	Solute (mL)	Total (mL)	v/v% (%)	Note

Example mixes

Ready-made examples you can adapt. Export for documentation.

#	Use case	Target v/v%	Total volume	Solute needed	Solvent needed
1	70% ethanol disinfectant	70%	1000 mL	700 mL	300 mL
2	3% hydrogen peroxide rinse	3%	500 mL	15 mL	485 mL
3	10% bleach cleaning solution	10%	2 L	200 mL	1800 mL

Formula used

The volume percent, v/v%, is defined as:

v/v% = (V_solute / V_solution) × 100%

Volume from mass and w/v%: V_solution(mL) = (100 × m_solute(g)) ÷ (w/v%)
If timing a fill: Q = V / t (e.g., mL/s or L/h)
All volumes must be in the same units before calculation.
Required solute for a target: V_solute = (v/v% ÷ 100) × V_solution
Mixing solute + solvent: V_solution = V_solute + V_solvent

How to use this calculator

Choose the tab matching your task.
Enter volumes and pick appropriate units.
Set decimal precision to control rounding.
Press the blue button to compute.
Click Add to log to record results.
Export the log to CSV or PDF as needed.

Assumes volumes are additive and temperature effects are negligible. For regulated processes, follow your SOPs.

Definition: w/v% = grams solute per 100 mL solution. So grams = w/v% × total(mL) ÷ 100.

Examples and v/v reference

Worked v/v example

Given a solute volume of 50 mL and a total solution volume of 200 mL, the volume percent is v/v% = (50 ÷ 200) × 100 = 25%. Use the button below to prefill and compute in the calculator.

Common v/v preparations

Use case	Target v/v%	Example total	Solute needed	Solvent needed
70% ethanol surface prep	70%	250 mL	175 mL	75 mL
25% glycerol stock	25%	100 mL	25 mL	75 mL
5% acetic acid solution	5%	1 L	50 mL	950 mL

Unit quick conversions for v/v workflows

1 L = 1000 mL · 1 mL = 1000 µL
1 US gal = 3785.411784 mL (≈ 3.785 L)
Convert units before computing; v/v% is unitless once normalized.

Frequently Asked Questions

1) What does volume percent (v/v%) actually mean, and when should I use it instead of w/v%?

Volume percent expresses the volume of a solute divided by the total solution volume, multiplied by 100. It is most appropriate for liquid-in-liquid mixtures, such as ethanol in water or fragrance oils in solvents. Weight per volume percent (w/v%) instead uses grams per 100 milliliters, which suits solids dissolved in liquids, like sodium chloride in water. Choose v/v% when both components are liquids and you are measuring by volume rather than mass or density-based conversions.

2) Are volumes always additive when I mix two liquids to reach a target v/v%?

Not always. Many laboratory calculations assume additive volumes for simplicity, but real liquids can contract or expand upon mixing due to molecular interactions. Classic examples include ethanol–water mixtures, which exhibit measurable volume contraction. For routine, non‑regulated work, assuming additivity is often acceptable. For high‑accuracy or regulated work, consult density tables, prepare to volume using calibrated volumetric glassware, and consider temperature control. When accuracy matters most, make up to final volume rather than summing component volumes arithmetically.

3) How precise are these calculations relative to my glassware, pipettes, or dispensers?

The computed values can display high numerical precision, but your real‑world accuracy depends on measurement tools and technique. Graduated cylinders typically offer lower precision than volumetric flasks or Class A pipettes. Automatic dispensers have manufacturer tolerances that grow at small set volumes. Temperature, meniscus reading, and calibration status also influence outcomes. Use the precision selector to match your reporting to realistic measurement capability, and document instruments, tolerances, and environmental conditions when reproducibility or compliance is required.

4) How do I scale a v/v% preparation up or down without changing concentration?

Keep the ratio between solute and total solution constant. For any new total volume, compute required solute as target v/v% divided by one hundred times the total volume. For example, 25% v/v requires twenty‑five milliliters solute per one hundred milliliters solution. To scale, multiply both volumes proportionally, then make up to the final volume using calibrated glassware. Avoid rounding until the final step, and record any deviations or top‑off adjustments used during preparation.

5) How should I document and export my v/v% calculations for audits or reproducibility?

Use the calculation log to capture inputs, units, modes, timestamps, and results. Add notes describing materials, batch identifiers, temperatures, and any top‑off to volume steps. Export the table as CSV for spreadsheets or PDF for fixed, shareable records. Store files alongside procedures, calibration certificates, and lot traceability. Consistent documentation ensures colleagues can reproduce your mixtures, enables trend analysis over time, and simplifies compliance reviews when external stakeholders request detailed preparation histories or verification evidence.