Campaign News

Here is the first draft of the carbon tax swap calculator… check it out and see how the CarbonWA proposal would affect your household!

How you can help: We would greatly appreciate your feedback in the Comments section below: Did everything make sense? Did you find any bugs? Do you have any questions? And (most of all) did you come out ahead?!?? Whether or not you came out ahead is actually quite important, so if you’re willing please post your location and maybe we’ll contact you about being an [anonymous] case study!

Also please share with your friends and neighbors! (And of course on your social networks: please like us on Facebook or follow us on Twitter.) And you can also help by coming to…

Outreach/fundraising meeting tomorrow in Seattle: Th Sept 25 at 7pm at Big Time on the Ave. Here’s a Facebook link; for more info email

PS. The calculator was a ton of work, and planned improvements in the months ahead will be another ton of work, so let’s take a minute to thank the folks whose work made this possible, starting with Summer Hanson, who did invaluable work on the methodology and will hopefully be back on the CarbonWA crew next summer after her junior year at Princeton; Justin Bare, who designed the website and wrote the computer code as his Masters degree project at UW; and yours truly, Yoram Bauman, and by the way I bear responsibility for any errors in the methodology. (See also this Excel version of the calculator: CarbonTaxCalculator11.) Additional thanks to UW Computer Science Professor Alan Borning, whose research includes a focus on “support[ing] civic engagement and deliberation“, and to the rest of the methodology team, which included Savannah KinzerAkua Konadu, and Lily Orth-Smith. Additional thanks to Marcia Baker and to all the volunteers (Alan, Aven, Dennis, Eileen, Gwen, Jane, Sharad, and Todd) who provided feedback on drafts!



Comments ( 27 )

  • Kyle M. says:

    I’m out about $50 per year – mostly due to my homes antiquated oil heating system. Of course, I can fix that deficit by shopping more and hopefully replacing my oil system with ductless or at least natural gas. (:

    Great job on the calculator!!

  • John Kydd says:

    Firstly, kudos on the effort!

    Second, some comments
    1. The introduction could be tightened to make it an easier read. Send me the text and I will edit it and you can use it or toss it.

    2. The calculator did not work for me in that it did not register the costs of the tax at the end. It noted taxes of NaN when the sections noted about $200 in annual taxes.

    3. Perhaps more detail is in order for therms and Kwh for the lay person. Tossing in just one sentence noting that 1 therm is 1.1 gallons of propane or natural gas and ___ gallons of diesel.

    4. You may wish to toss in that solar and wind are NOT subject to tax with a section showing how much tax was avoided by having some solar or wind power.

    5. Were I a business, where is the B and O calculator?

    6. Many people have an idea of annual mileage on cars but not annual gallonage. Perhaps consider inserting a space for annual miles and avg mileage.

    7. Some commuters will note that this could increase bus and ferry fares…ferries are very carbon intensive….how do we capture the additional cost or highlight that carbon tax will not apply to ferries and public transit??

    Hope this is of some help.

    John Kydd

    • Yoram Bauman says:

      Thanks John!

      1) You can just copy the text from, yes? Your edits welcome.

      2) Can you replicate the steps that got you that “NaN” reading? There’s a bug in there somewhere…

      3) and 4) Probably too much detail for right now.

      5) As it says on the home page, business calculator coming soon!

      6) Good idea, this is on our to-do list.

      7) Right now we have an exemption for public transit fuel but we’re debating about whether to exempt ferry fuel. I suppose after we figure that out we can decide whether or not to include some details about this, but it’s a pretty fine level of detail.

  • Rob Briggs says:

    Nice job!

    For gasoline you offer the option of entering usage as either gallons or dollars and for either week, month, or year.

    I would suggest enabling users to also enter home energy usage in energy units or in dollars and either per month or per year.

    • Yoram Bauman says:

      Interesting idea, Rob, but how are people going to know how much they spend on energy without looking at their bill? And if they’re looking at their bill then they should be able to get the information we’re asking for, yes? And PS. I think doing this monthly is going to be too tricky anyhow because some people smooth out their energy payments over the year and some people don’t. (I think many utilities offer to charge you a fixed amount every month so that you don’t see a big bill in the winter and a small bill in the summer.)

  • sparklee says:

    Given that one of the goals is a shift away from carbon, it would make sense to contrast the higher cost of driving a gas car with the lower cost of an electric vehicle. This relationship is hidden somewhat by the seperation of gasoline usage and home electricity usage. Perhaps those could be combined somehow.

  • Chris Feise says:

    For educational purposes I would like to see information on the rate of the carbon tax.

    For auto use, I have to give my insurance company an annual mileage estimate. I know that number. When I estimated gallons of gasoline per time period in the calculator I underestimated by 50% which I discovered when I used my known annual mileage number and divided by my car’s average miles per gallon. giving an annual mileage might be another option (this assumes the person knows their average miles per gallon).

    I was not asked for my electricity usage. I assume this will not be part of the calculation since we are hydro heavy users in Seattle. Correct?

    Good job!

    • Yoram Bauman says:

      Thanks Chris!

      1) You’re right that there’s no information about the rate of the carbon tax, just a link to Maybe that’s a bug (not enough information) and maybe that’s a feature (keep it short and sweet)… I’ll share your request on that.

      2) Yes on annual mileage. (You’re the 2nd person to suggest this now, plus one of our early volunteer testers suggested this as well… it just didn’t make the cut for the first round implementation.)

      3) Electricity usage is part of the Home Energy Usage section, yes?

  • Dave Kozin says:

    Worked great for me! According to the calculator, our household would save $76 per year living in Seattle.

  • Fran Koehler says:

    Worked fine for me, easy to do. We would save about $300 per year.
    The one thing it didn’t capture is the fact that we don’t pay anything for electricity now, thanks to our solar photo-voltaic system. So that presumably led to a small underestimation of our savings.

    • Yoram Bauman says:

      Thanks Fran! And you’re right about solar PV; it would be better to indicate that we’re just asking for how many kWhs you buy from your utility, so that you should not count anything you generate yourself.

  • Denis Martynowych says:

    The calculator worked smoothly.

    Was there some way to note the environmental benefit along side the personal impact on the summary page. Perhaps it just notes the estimated per capita carbon savings

    • Yoram Bauman says:

      Good idea, but the calculator currently doesn’t make any estimate of how much carbon you might be able to save; it just estimates your carbon tax payments based on your past behavior. We are thinking of adding an indication of how many tons of CO2 your household emits… but again that’s a measure related to your carbon tax payments and not to potential savings or environmental benefit. Ideas???

  • Chris Greacen says:

    Worked great, and showed our family would have savings of about $150 per year. Our situation: drive very little, live in solar powered net-zero energy home (we actually produce more electricity than we use every year), no heating fuel costs, but we fly a fair amount — 24000 miles to Thailand.

    • Chris Greacen says:

      One additional thought — right now the sales tax savings calculation appears to be based entirely on household income. This makes assumptions about how much families are saving (investing, putting in savings accounts, etc.). Clearly income doesn’t necessarily equal expenditures. I wonder if it would make sense to add a field to account for how much a family is putting away rather than spending.

  • John Kydd says:

    Here is my attempt at editing the introductory text

    Here is the unedited text

    You can use the following online calculator to estimate how one specific carbon tax proposal would impact you and your household financially. The specific proposal, from, would impose a carbon tax and use the revenues to reduce sales taxes and business taxes, and to fund a Working Families Rebate for low-income households. This website is not intended to advocate for or against this policy, but to provide an unbiased estimate of the impacts of the policy. It will show you an estimate of the amount of money you would save from the reduced sales tax and the Working Families Rebate. It will also show you an estimate of the amount you would pay from the new tax on the burning of fossil fuels, from activities such as driving a vehicle, flying on an airplane, and powering and heating your home. Most users should be able to complete this calculator in about 10 minutes.

    The calculator for businesses is coming soon!

    If you have any feedback about this website, please contact us

    Here is the edited text.

    While we all benefit from burning less carbon, the cost of this tax should be offset by a reduction in our sales tax and a Working Families Rebate for low income households. The only way to prove the actual impact is to provide a calculator that estimates the impact on your household.

    This calculator shows:

    1. What your household would save from the reduced sales tax and the Working Families Rebate and
    2. What you would pay for your use of fossil fuels from activities such as driving a vehicle, flying on an airplane, and powering and heating your home.

    Most users should be able to complete this calculator in about 10 minutes. The calculator for businesses is coming soon!

    If you have any feedback about this website, please contact us

  • Bob Lynette says:

    Worked well. We retired living mostly off Social Security. We would get a small rebate.

  • Bruce Bonifaci says:

    A straightforward approach which posed no problems. Turns out we’d come out $380 for the worse here in Poulsbo.

  • Rogers Weed says:

    Hi CarbonWA,

    Gave the calculator a try. Worked just fine for me. We end up down ~$150 for the year owing to the fairly extensive air travel our family of five does, but that would be a small price to pay for the economy-wide benefits of finally having a price on carbon!


  • Tom Hundley says:

    The Carbon tax swap calculator is so easy to utilize. It even prompted me with suggestions about rough estimates for the Home Energy Usage category, which helped since I didn’t have ready access to our kWh usage.

    Based on the calculator’s data, when Initiative Measure No. 673 gets voted into law, my household will see quite meaningful sales tax savings along with a significant Working Families Rebate.

    Along with ease of use, the calculator is presented in an appealing manner, which feels welcoming and encourages exploration.

    Great work!

  • Debra says:

    We drive with mostly bio-diesel, will there be a tax on that?
    Nice job, and fun to figure out, and yes, we came out over $350 to the good without calculating any gasoline taxes.

  • Daniel Malakey says:

    I love this calculator!

    It didn’t take me long to work through it and and our household would come out ahead by several hundred dollars. We are a one car family, take transit or bike to work, and have an energy-efficient house so the sales tax savings were much greater than the increase to our home heating and gas bill. Nice work, Yoram and team!


  • Nic Warmenhoven says:

    Calculator worked smoothly. My household squeaked through with $15 savings per year. I was shocked that ~60% of our taxes were based on electricity usage — guess there’s something about our hydrosystem that I don’t understand?

Leave A Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.