Turn therm data into savings forecasts fast today. Add rates, fees, and upgrade cost options. Download results as CSV or PDF for sharing easily.
Sample inputs and expected style of outputs. Your totals will differ based on rates, fees, and timeframe.
| Scenario | Therms | Price/Therm | Fixed/Month | Year 1 Savings |
|---|---|---|---|---|
| Baseline | 1200 / year | $1.55 | $15.00 | — |
| Efficiency upgrade | 1020 / year | $1.55 | $15.00 | $279.00 |
| Rate change + upgrade | 1020 / year | $1.40 | $15.00 | $432.00 |
Therm spending is the sum of variable usage charges and fixed monthly fees, then any taxes or surcharges. This calculator models both parts so your estimate mirrors a real bill structure, not only a simple therms times rate shortcut. Results show year‑one savings and a full multi‑year schedule.
Start with baseline therms from recent statements. You can enter a new therm value directly, or leave it blank and use a reduction percent for an upgrade scenario. If you track usage monthly, select monthly input and the tool annualizes totals to compare projects consistently. Therms saved feed both cost and emissions outputs.
Gas tariffs can change, and fixed charges may rise as well. The escalation input applies compound growth to the per‑therm rate and fixed fees each year. You can also model a different future price per therm after switching plans, negotiating supply, or moving to a new service area. These levers often change savings more than small efficiency tweaks.
Upgrade cost enables decision metrics. Payback is the first year cumulative savings exceed the initial cost, giving a practical “how fast” view. Simple ROI compares total savings to cost over the chosen horizon. NPV discounts future savings using your discount rate, so a dollar next year is worth less than a dollar today. Net NPV subtracts the upgrade cost from discounted savings.
The Plotly chart plots baseline cost, new cost, and annual savings by year to highlight how escalation affects the gap. Look for widening separation, which indicates compounding benefits. If savings stay flat, the project is mainly a one‑time reduction. Use the CSV to share assumptions with stakeholders and the PDF to document outcomes for approvals. For sensitivity, rerun with higher therm prices or lower reductions; the range helps set conservative targets. When comparing multiple upgrades, keep the period and years constant for apples‑to‑apples evaluation across teams and budgets.
A therm is a unit of heat energy commonly used for natural gas billing. It represents a fixed amount of energy delivered, regardless of the gas volume needed to supply that energy.
Use monthly if you record usage from each bill and want the tool to annualize automatically. Use annual if you already summed 12 months or have a yearly estimate from your provider.
Enter an average price per therm that reflects your typical blended rate, including seasonal patterns. For more precision, run separate scenarios for low and high seasons and compare the combined annual totals.
Yes. Fixed charges reduce the portion of the bill affected by usage reductions. Modeling them separately prevents overestimating savings when the rate component is smaller than expected.
The calculator adds annual savings year by year until the cumulative total equals or exceeds the upgrade cost. The first year that happens is reported as the payback year.
Yes. The tool converts therms saved to avoided CO2 using the kg CO2 per therm factor. Replace the default with your local or program requirement for consistent reporting.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.