Bromine Dose Calculator

Inputs

All ppm values are treated as mg/L on a Br2-equivalent basis.

Water volume

Reservoir, tank, pond, or mixing tote volume.

Volume unit

Choose the unit you measure in.

Current bromine (ppm)

From your most recent test.

Target bromine (ppm)

Set a goal residual for your system.

Demand allowance (ppm)

Extra to cover losses from organics and sunlight.

Safety margin (%)

Auto-limited to 0–50% to prevent extremes.

Product form

Affects how the dose is displayed.

Available bromine (%)

Use the label value for “available” or “active” bromine.

Liquid density (g/mL)

Needed to convert grams to milliliters.

Rounding

Smart reduces noise without hiding scale.

Notes (optional)

These notes are saved into your export history.

Saved Calculations

Up to 20 recent entries are stored in this browser session.

No saved results yet. Run a calculation to start a log.

Example Data Table

These examples show typical inputs and the computed product dose. Replace with your own label percent and tested readings.

Scenario	Volume	Current (ppm)	Target (ppm)	Demand (ppm)	Available (%)	Dose
Small reservoir, light demand (liquid)	500 L	0.3	2.0	0.2	10%	~ 95 mL (density 1.20)
IBC tote, shaded (granular)	1000 L	0.0	2.0	0.1	65%	~ 3.2 g
Pond top-up, higher demand (liquid)	2500 L	0.5	3.0	0.5	12.5%	~ 700 mL (density 1.20)

Formula Used

This calculator treats ppm as mg/L for dilute water solutions.

1) Convert volume to liters:
L = input × 3.785411784 (US gal) or L = input × 4.54609 (UK gal)
2) Effective ppm increase:
Δppm = max(0, target − current)
effective = (Δppm + demand) × (1 + safety%/100)
3) Active bromine required:
active_g = effective(ppm) × liters / 1000
4) Convert to product amount:
product_g = active_g / (available%/100)
For liquids: product_mL = product_g / density(g/mL)

How to Use This Calculator