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Size Calculator Best-Of
Free Interactive Tools

Water & Plumbing Calculators

Expert-calibrated tools backed by our database of 500+ products. Get instant, personalized answers — no signup required.

24
Free tools
500+
Products in DB
8
Categories covered

Water Heaters Tools

Browse Water Heaters →
Water Heater Size Calculator
Find the right tank capacity or GPM flow rate for your household.
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Water Heater Energy Cost Calculator
Calculate annual operating costs and savings from upgrading.
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Water Heater Troubleshooting Guide
Diagnose your problem with a step-by-step symptom checker.
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Recovery Time Calculator
See how many minutes your tank needs to reheat after heavy use.
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Tank vs. Tankless Wizard
Answer 6 questions and get a scored recommendation: tank, tankless, or heat pump.
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Installation Cost Estimator
Get a line-item cost breakdown for tank, tankless, and heat pump installation.
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Gas vs. Electric Cost Calculator
Compare true annual running costs side-by-side with your utility rates.
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Flush Interval Calculator
Find out when to flush your water heater based on hardness and age.
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Toilets Tools

Browse Toilets →
Toilet Water Savings Calculator
Discover your annual savings from upgrading to a WaterSense toilet.
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Running Toilet Waste Calculator
Find out how much a leaking toilet is costing you per year.
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Toilet Rough-In Finder
Measure your rough-in, find every toilet that fits your bathroom.
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How to Choose a Toilet
Answer 5 questions about your bathroom and get matched toilets.
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Repair vs. Replace Advisor
Score your toilet's condition and find out whether to fix it or replace it.
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Bidets Tools

Browse Bidets →
Bidet vs Toilet Paper Calculator
See how quickly a bidet pays for itself vs. buying toilet paper.
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Water Softeners Tools

Browse Water Softeners →
Water Softener Size Calculator
Get the right grain capacity based on hardness, iron, and household size.
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Salt Usage Calculator
Calculate monthly salt usage and annual cost for your softener.
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Hard Water Cost Calculator
See exactly what hard water costs you in appliance damage and energy loss.
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Water Softener vs. Water Filter
Answer 5 questions and get a personalized softener vs. filter recommendation.
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Water Filters Tools

Browse Water Filters →
Water Filter Type Selector
Find the right filter type for your water quality concern and budget.
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Filter Replacement Schedule
Get a personalized replacement schedule and annual cost for every filter stage.
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Faucets Tools

Browse Faucets →
Faucet Drip Cost Calculator
Find out exactly how much a dripping faucet costs you per year.
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Bathtubs & Showerheads Tools

Browse Bathtubs & Showerheads →
Bathtub to Shower Conversion Cost
Estimate total conversion cost from liner swap to custom walk-in tile.
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Showerhead Flow Rate & Savings
Calculate annual water and energy savings from a low-flow showerhead upgrade.
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Whole-Home Tools Tools

Browse Whole-Home Tools →
Whole-Home Water Savings Calculator
See your total potential savings across every fixture — toilet, shower, faucets, and appliances.
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Why use WaterClue tools?

🎯

Backed by real product data

Every recommendation is matched against our database of 500+ products with verified specs — not generic advice.

⚡

Instant results, no signup

All calculations run client-side in your browser. No account needed, no email required, no waiting.

🔢

Calibrated to industry standards

Our formulas use EPA, DOE, and ANSI standards — First Hour Rating, UEF, MaP scores, and WaterSense criteria.

💰

Real dollar figures

We calculate actual annual costs at your local water rate, not vague "save up to X%" marketing claims.

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Built for homeowners

Plain-language results you can act on immediately — no plumbing degree required to understand the output.

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Updated every year

Cost figures, energy rates, and WaterSense standards are reviewed annually so your estimates stay accurate.