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Find Water Hardness by Location or Zip Code Check Local Water Hardness Levels Instantly

Interactive Map

Enter your zip code to instantly see your local water hardness level in GPG and PPM, plus get personalized treatment recommendations.

Finding water hardness data...

Soft (0-60 PPM)
Moderate (61-120 PPM)
Hard (121-180 PPM)
Very Hard (180+ PPM)

How to Check Your Water Hardness

Find your local water hardness level in seconds using our interactive map. No account required.

1

Enter Your Zip Code

Type your 5-digit zip code into the search box above, or click "Use My Location" to automatically detect your area using GPS.

2

View Your Water Hardness

Instantly see your local water hardness in GPG and PPM, plus a color-coded classification showing if your water is soft, moderate, hard, or very hard.

3

Get Personalized Solutions

Based on your hardness level, we'll recommend the right water treatment options—from water softeners to salt-free conditioners—sized for you.

Hardest Water Regions in the U.S.

Some areas have extremely hard water that can cause significant scale buildup and appliance damage. Here are the regions with the highest water hardness levels.

What States Have the Hardest Water?

  • 1 Indiana
    298 PPM
  • 2 Arizona
    280 PPM
  • 3 Texas
    268 PPM
  • 4 Utah
    259 PPM
  • 5 New Mexico
    252 PPM

Which Cities Have the Hardest Water?

  • 1 Fort Stockton TX
    1,850 PPM
  • 2 Niland CA
    1,420 PPM
  • 3 Westmorland CA
    1,250 PPM
  • 4 Calexico CA
    890 PPM
  • 5 Ventura CA
    666 PPM

Water hardness above 180 PPM (10.5 GPG) is considered "very hard" and treatment is strongly recommended. Find the right water softener for your home.

Understanding the Water Hardness Scale

Water hardness is measured in grains per gallon (GPG) or parts per million (PPM). Here's how to interpret your results and what they mean for your home.

0 - 3.5 GPG 3.5 - 7 GPG 7 - 10.5 GPG 10.5+ GPG

Soft Water

0 - 3.5 GPG
0 - 60 PPM

Moderately Hard

3.5 - 7 GPG
61 - 120 PPM

Hard Water

7 - 10.5 GPG
121 - 180 PPM

Very Hard

10.5+ GPG
180+ PPM

GPG to PPM Conversion Chart

GPG PPM (mg/L) Classification Treatment?
0 - 1 0 - 17 Soft No
1 - 3.5 17 - 60 Slightly Hard Optional
3.5 - 7 60 - 120 Moderately Hard Recommended
7 - 10.5 120 - 180 Hard Yes
10.5 - 15 180 - 257 Very Hard Yes
15+ 257+ Extremely Hard Essential

Signs & Effects of Hard Water

Hard water affects 85% of American homes. Recognize any of these signs of hard water? These problems indicate mineral buildup is damaging your home, appliances, and quality of life.

Failed water heater element covered in calcium scale buildup from hard water

Appliance Damage

Scale buildup shortens the lifespan of water heaters, dishwashers, and washing machines by years.

Stiff scratchy towels with faded colors caused by washing in hard water

Stiff, Faded Laundry

Hard water traps detergent in fibers, making clothes scratchy and colors fade faster.

White chalky limescale buildup on chrome faucet from hard water

Crusty Scale Buildup

White chalky deposits on faucets and showerheads that require heavy scrubbing.

Person with dry irritated skin from bathing in hard water

Dry, Itchy Skin

Soap scum clogs pores, causing irritation, dryness, and eczema flare-ups.

Wine glasses with cloudy water spots from hard water

Spotty Glassware

Dishes come out cloudy with water spots that never fully come clean.

Weak water stream from showerhead clogged with mineral deposits

Low Water Pressure

Scale narrows pipe diameter, reducing flow to showers and faucets.

What This Means for You

Understanding your water hardness level helps you make informed decisions about water treatment for your home.

Map Data vs. Actual Testing

Our map shows regional averages: Water hardness can vary within the same zip code depending on your water source, whether you're on city water or a private well, and seasonal changes.

For precise results: We recommend testing your water directly, especially if you're on well water or planning to purchase a water treatment system.

When to Take Action

Above 7 GPG (120 PPM): Water is considered "hard" and will likely cause noticeable scale buildup, dry skin, and reduced soap lathering. A water softener is recommended.

Above 10 GPG (180 PPM): Water is "very hard" and can significantly reduce appliance lifespan, clog pipes, and increase energy bills. Treatment is strongly advised.

Frequently Asked Questions

Everything you need to know about water hardness and what it means for your home.

Water hardness refers to the concentration of dissolved minerals—primarily calcium and magnesium—in your water. These minerals are picked up as water travels through soil and rock. Hardness is measured in grains per gallon (GPG) or parts per million (PPM). For a deeper understanding, read our complete guide to hard water.

Hard water is caused by groundwater dissolving calcium and magnesium from limestone, chalk, and other mineral deposits as it flows through the earth. Geographic regions with more limestone bedrock tend to have harder water. Learn more about what causes hard water and why it varies by location.

Yes, hard water is safe to drink and may even provide beneficial minerals like calcium and magnesium. However, hard water causes problems with scale buildup, dry skin, spotty dishes, and reduced appliance efficiency—which is why many people choose to treat it.

You can test water hardness using a home test kit, by checking your municipal water quality report (for city water), or by having a professional lab analysis done. Our map provides regional averages, but testing gives you exact results for your specific water supply. See our guide on how to test water hardness for step-by-step instructions.

GPG (grains per gallon) and PPM (parts per million) are both units for measuring water hardness. To convert PPM to GPG, divide by 17.1. For example, 171 PPM equals 10 GPG. Water treatment equipment typically uses GPG for sizing. For quick and simple conversions, use our conversion calculator and save yourself time on the math.

Water above 7 GPG (120 PPM) is considered hard and will benefit from a water softener. Water above 10.5 GPG (180 PPM) is very hard, and treatment is strongly recommended to protect plumbing and appliances.

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Complete Solution

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The ultimate hard water solution combining ion-exchange softening with multi-stage filtration for soft, clean, great-tasting water from every tap.

Removes hardness minerals (calcium & magnesium)
Pre-filter removes sediment & chlorine
Post-filter polishes for crystal clear water
Protects appliances & extends lifespan
Softer skin & hair after every shower
Made in USA with premium components
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48-60k
Grain Capacity
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Ready to Fix Your Hard Water?

Now that you know your water hardness level, take the next step. Browse our selection of water softeners and whole house filters, or use our sizing calculator to find the perfect system for your home.

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Learn More About Water Hardness

Explore our guides and resources to understand water hardness, treatment options, and how to choose the right solution for your home.

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