Water hardness lookup

Check water hardness before buying a softener or filter.

Hardness is about calcium and magnesium, not every water-quality concern. Start with a city profile, a state guide, or the hardness-by-city table.

Start here

Water hardness by city

Hardest water cities

State guides

Arizona

Arizona guide for Phoenix, Scottsdale, Mesa, Tucson, and desert hard-water context.

Nevada

Nevada guide for Las Vegas, Reno, very hard water, and TMWA/provider matching.

Texas

Texas guide for Houston, Austin, Dallas, San Antonio, El Paso, and large utility variation.

Florida

Florida guide for Tampa, Orlando, Miami, Jacksonville, Gulf Coast cities, and city/county utility differences.

California

California guide for Los Angeles, San Diego, San Jose, Bakersfield, Riverside, and provider-boundary issues.

Utah

Utah guide for Salt Lake City and source-dependent hard-water ranges.

New York

New York guide for NYC, Long Island, watershed water, and district/provider differences.

Ohio

Ohio guide for Cleveland and system-specific hardness context.

Pennsylvania

Pennsylvania guide for Philadelphia, Pittsburgh, and local source/provider context.

Colorado

Colorado guide for Denver and Colorado Springs source and seasonal variation.

Oregon

Oregon guide for Portland, Eugene, Bull Run supply, and groundwater differences.

Tools

Hardness Converter

Convert ppm or mg/L to grains per gallon.

Softener Sizing

Estimate a planning range.

Filter vs Softener

Separate hardness issues from contaminant questions.

Browse state hardness guides

Arizona

Arizona guide for Phoenix, Scottsdale, Mesa, Tucson, and desert hard-water context.

California

California guide for Los Angeles, San Diego, San Jose, Bakersfield, Riverside, and provider-boundary issues.

Colorado

Colorado guide for Denver and Colorado Springs source and seasonal variation.

Florida

Florida guide for Tampa, Orlando, Miami, Jacksonville, Gulf Coast cities, and city/county utility differences.

Georgia

Georgia guide for Atlanta and local provider/source context.

Idaho

Idaho guide for Boise-area provider matching and local report context.

Illinois

Illinois guide for Chicago and Lake Michigan source context.

Indiana

Indiana guide for Indianapolis and Citizens Energy Group context.

Maryland

Maryland guide for Baltimore DPW and local testing considerations.

Massachusetts

Massachusetts guide for Boston, MWRA supply, and local building context.

Michigan

Michigan guide for Detroit, Grand Rapids, and local utility differences.

Minnesota

Minnesota guide for Minneapolis and local treatment context.

Nevada

Nevada guide for Las Vegas, Reno, very hard water, and TMWA/provider matching.

New Mexico

New Mexico guide for Albuquerque and ABCWUA reporting.

New York

New York guide for NYC, Long Island, watershed water, and district/provider differences.

North Carolina

North Carolina guide for Charlotte, Raleigh, Durham, and city utility context.

Ohio

Ohio guide for Cleveland and system-specific hardness context.

Oregon

Oregon guide for Portland, Eugene, Bull Run supply, and groundwater differences.

Pennsylvania

Pennsylvania guide for Philadelphia, Pittsburgh, and local source/provider context.

Tennessee

Tennessee guide for Memphis, Nashville, aquifer, and Metro Water Services context.

Texas

Texas guide for Houston, Austin, Dallas, San Antonio, El Paso, and large utility variation.

Utah

Utah guide for Salt Lake City and source-dependent hard-water ranges.

Washington DC

Washington, DC guide for DC Water, Washington Aqueduct, and building plumbing context.

Washington

Washington guide for Seattle, Tacoma, watershed context, and provider details.

Wisconsin

Wisconsin guide for Milwaukee and Lake Michigan source context.