Volume Distribution Calculator

Inputs

Choose a distribution method and list your components. Add rows as needed.

Total volume *

Unit *

Mode *

Rounding decimals

Normalize inputs to 100%

Useful if values don't sum perfectly.

Estimate mass from density (g/mL)

Adds optional density field per component.

Components

Enter values as percentages.

Component name	Value	Density (g/mL)

Example Data Table

Example: 1000 mL total distributed by percentages.

Component	Percent	Calculated Volume (mL)	Typical Density (g/mL)	Estimated Mass (g)
Water	70%	700	0.997	697.9
Ethanol	20%	200	0.789	157.8
Acetonitrile	10%	100	0.786	78.6

Mass values are approximate and depend on temperature and purity.

Formula Used

Percent mode

If the total volume is V and the component percentage is p, then:

Vᵢ = V × (p / 100)

When normalization is enabled, percentages are adjusted as:

p′ = p / Σp × 100

Ratio mode

If the component has rᵢ parts out of total parts Σr, then:

Vᵢ = V × (rᵢ / Σr)

Fixed volumes

Enter direct component volumes. If Auto remainder is enabled, the final component is:

V_last = V_total − ΣV_other

Optional mass estimate

Convert computed volume to mL, then multiply by density (g/mL):

m (g) = V (mL) × ρ (g/mL)

How to Use This Calculator

Enter the total target volume and choose a unit.
Select a mode: Percent, Ratio, or Fixed volumes.
Add each component name and its value for the chosen mode.
Enable Normalize if your entries do not sum perfectly.
Optionally enable mass estimation and enter densities.
Press Submit to view results above the form, then export.

Why volume distribution matters in mixture design

Accurate volumetric splits reduce batch variability, especially when preparing mobile phases, buffers, or solvent blends. A 1,000 mL target that drifts by 2% can shift composition enough to change retention times, viscosity, or reaction rates. Using a consistent calculation step keeps preparation repeatable across operators and sites in regulated environments.

Percent, ratio, and fixed-volume workflows

Percent mode allocates volumes directly from stated percentages, ideal for published recipes like 70/20/10 blends. Ratio mode converts “parts” into fractions, useful when protocols specify 3:1:1 or 5 parts solvent A to 2 parts solvent B. Fixed-volume mode supports direct dispensing, and the auto-remainder option computes the last component so totals close exactly.

Normalization and rounding control

Real inputs rarely sum perfectly due to rounding or measurement limits. Normalization rescales entries so the effective percentages total 100% while preserving relative proportions. For example, 49.9%, 25.0%, and 25.2% sum to 100.1%; normalization adjusts each slightly to match the total. Rounding controls help align calculations with glassware resolution, such as 0.1 mL for pipettes or 1 mL for cylinders.

Density-based mass estimates for preparation

When densities are provided in g/mL, the calculator estimates mass as m = V × ρ after converting volumes to mL. This is helpful for documentation or for weighing additions when volumetric transfer is inconvenient. For instance, 200 mL ethanol at 0.789 g/mL corresponds to about 157.8 g. Leave density blank to skip mass without affecting volume distribution.

Quality checks and common lab scenarios

Built-in checks flag negative values, missing entries, and totals that exceed the target. Fixed volumes can be validated within a small tolerance to accommodate rounding. Typical scenarios include solvent gradients, quench mixtures, diluent preparation, and reagent cocktails where one component is “fill to volume.” Use auto-remainder for that fill step to avoid cumulative error.

Exportable records and reproducible protocols

CSV export supports lab notebooks and LIMS uploads, while PDF snapshots provide shareable batch records. Recording the total volume, mode, and rounding setting makes recipes auditable. If a method changes, you can update only the inputs and regenerate a consistent distribution table and chart for each new batch.

FAQs

1) Which mode should I use for solvent blends?
Use Percent mode for published compositions like 70/20/10. Use Ratio mode when procedures specify parts, such as 3:1. Use Fixed volumes when you already know dispense volumes or want a final fill-to-volume remainder.

2) What does Normalize do?
Normalize rescales your inputs so the effective percentages sum to 100 while keeping the same proportions. It is helpful when your entries sum to 99.8% or 100.3% because of rounding or measurement limits.

3) How does Auto remainder work in Fixed volumes?
When enabled, the last component is calculated as total volume minus the sum of all other fixed volumes. This matches common lab steps like “add solvent, then bring to volume” and prevents cumulative rounding error.

4) Why are my totals rejected in Percent mode?
If normalization is off, Percent mode requires the inputs to sum to 100 within a small tolerance. Turn on Normalize, or adjust your values so the total is exactly 100 for strict recipe control.

5) Does density affect the volume calculation?
No. Volume distribution is computed only from the total and the selected mode. Density is optional and is used only to estimate mass in grams from the calculated mL values for labeling or documentation.

6) What exports are available?
Download CSV for spreadsheets, notebooks, or LIMS uploads. Download PDF for a shareable snapshot with the same table shown on screen. Run a calculation first so the export uses your most recent results.