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Tankless Water Heater Savings Calculator

Tankless water heaters avoid the standby losses of keeping a full tank hot. This calculator estimates your yearly saving and how long the upgrade takes to pay back.

Change any number below — your result updates instantly, no button to click.

Your details

$ /yr

Yearly cost to heat your water now.

%

Tankless units commonly save 8–35% versus a storage tank.

$

Results

Estimated yearly saving
Payback period

Years until the upgrade pays for itself.

Net saving over 10 years
Optional next step

Measure or improve the real-world result

These tools are relevant to the numbers above; you do not need them to use the calculator.

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Written & maintained by the HowMuchWatts team · Last updated June 30, 2026 · How we verify our numbers

How it works

Yearly saving = current water heating cost × saving % ÷ 100. Payback = upgrade cost ÷ yearly saving. The 10-year figure is 10 years of savings minus the upgrade cost. Tankless heaters also last longer and free up space — benefits not counted here.

Frequently asked questions

How much do tankless heaters save?

Typically 8–35% on water heating energy, with the biggest savings for low-to-moderate hot water use where standby tank losses dominate.

Are they worth the higher upfront cost?

It depends on the saving and install cost — the payback above tells you. They also last longer (often 20+ years) and never run out of hot water.

What is standby loss?

The energy a storage tank wastes keeping water hot around the clock, even when no one uses it. Tankless heaters avoid this by heating on demand.

These calculators provide general estimates for educational purposes only and are not financial advice. Real-world results depend on factors not captured here. Verify figures independently before making any purchase or financial decision.
Complete topic guide Home Heating & Cooling Costs Compare heating and cooling running costs, seasonal efficiency, upgrades, and payback with transparent calculators and practical decision guidance.

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