Updated Science

Water Hardness Calculator

Convert water hardness units, interpret hardness levels, estimate hardness from calcium & magnesium, and plan water softener regeneration and salt usage.

Unit Converter Hardness Scale Ca & Mg Method Softener Planner

Water Hardness Conversion, Classification & Planning

Convert between common hardness units, label soft vs hard water, calculate hardness from Ca/Mg, and estimate softener regeneration and salt needs.

Hardness value

Input unit

Decimals

Export

Calcium (Ca) concentration

Magnesium (Mg) concentration

Input unit

Decimals

Export

Hardness value

Unit

Classification scale

Decimals

Export

Water hardness

Hardness unit

Water use input

People

Gallons per person per day

Total gallons per day

Softener capacity mode

Capacity per regeneration (grains)

Salt per regeneration (lb)

Preset (capacity per ft³, planning)

Reserve factor

Decimals

Export

Schedule start date

Months to generate

Use Softener Planner interval

Manual interval (days)

Max rows

Export

Water Hardness Calculator

Water Hardness Conversion, Classification & Planning

mg/L (ppm) as CaCO₃

Grains per gallon

German degrees (°dH)

French degrees (°fH)

Total Hardness (mg/L as CaCO₃)

Calcium Hardness (as CaCO₃)

Magnesium Hardness (as CaCO₃)

Equivalent gpg

Hardness (mg/L as CaCO₃)

Hardness (gpg)

Category

What this often affects

Hardness (gpg)

Daily load (grains/day)

Regen interval (days)

Salt estimate (lb/month)

Water Hardness Calculator

Water Hardness Conversion, Classification & Planning

mg/L (ppm) as CaCO₃

Grains per gallon

German degrees (°dH)

French degrees (°fH)

Total Hardness (mg/L as CaCO₃)

Calcium Hardness (as CaCO₃)

Magnesium Hardness (as CaCO₃)

Equivalent gpg

Hardness (mg/L as CaCO₃)

Hardness (gpg)

Category

What this often affects

Hardness (gpg)

Daily load (grains/day)

Regen interval (days)

Salt estimate (lb/month)

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