How Per Year calculates yearly costs

Weekly bills

A weekly bill is multiplied by 52 to get the year. There are 52 weeks in most years (52.14 in a precise calculation, but the standard convention is 52).

The monthly equivalent is calculated by dividing the yearly total by 12, which gives you an average month. This is useful for comparing weekly bills to monthly bills in your budget.

Monthly bills

A monthly bill is multiplied by 12 to get the year. This is the most common cadence for subscriptions, utilities, rent, and insurance premiums.

If your bill varies month to month (like electric in summer vs winter), enter an average monthly amount or use the highest month to see the upper bound of your annual cost.

Yearly bills

A yearly bill stays as you entered it. Annual insurance premiums, membership renewals, and subscription upgrades paid once per year are already in yearly terms.

The free total's monthly equivalent is yearly ÷ 12. The paid Annual Bills Plan uses that same calm monthly for irregular bills, plus a separate catch-up seed (below) when you start mid-cycle.

Quarterly and every-6-months bills

Quarterly bills multiply by 4. Bills charged every 6 months multiply by 2. Older saved lists and share URLs that only used week, month, or year keep working unchanged.

Steady monthly + catch-up seed (Annual Bills Plan)

Yearly, quarterly, and every-6-months bills annualize into one steady monthly set-aside (total yearly sinking ÷ 12) — the same number whether you start in January or October. A separate catch-up seed is the amount the reserve would go short before the next due dates if you only made those level deposits (plus any electric seasonality cushion). That keeps the hero "$X/mo" calm while staying honest about near dues — the same pattern as YNAB underfunded targets and utility bill-smoothing true-ups. The free calculator only shows a masked digit count of the steady monthly — never the dollars or the catch-up lump — until purchase.

Electric seasonality (EIA-861M)

Variable monthly electric bills use residential seasonality indices derived from EIA Form EIA-861M Sales and revenue (2025) (2025; last verified 2026-10-23). Average monthly bill = (revenue in thousand dollars × 1000) ÷ customers. Each month's index is that month's bill ÷ the state's 12-month mean. When a U.S. state is known, that state's curve is used; otherwise the national aggregate curve. The twelve shaped months still sum to the typed yearly electric total — no invented multipliers.

Per-use costs

Some bills are paid per use rather than on a fixed schedule: parking fees, transit passes, laundry, or occasional services. Per Year lets you enter a per-use price and how many times per month you use it.

The per-use price is multiplied by uses per month to get a monthly equivalent, then that monthly cost is multiplied by 12 to get the yearly total. This lets you model variable costs that still recur predictably.

How bills are totaled

Once every bill is converted to a yearly cost, Per Year adds them up. The sum is your total annual recurring cost. The monthly equivalent shown on the calculator is the yearly total divided by 12, which represents the average month if you spread the year evenly.

Each bill is also converted to a monthly equivalent for display. This helps you compare bills on different cadences: a $6/week coffee habit ($26/month) is more expensive than a $15.99/month streaming service.

BLS comparison (Annual Bills Plan only)

The one-time Annual Bills Plan includes a comparison to Bureau of Labor Statistics (BLS) data when you provide your household size. The BLS publishes annual Consumer Expenditure Surveys that report average spending by household size across categories like housing, transportation, food, and healthcare.

The report compares your entered bills to the BLS averages in matching categories. For example, if you entered $400/month in food costs, the report shows how that compares to the average food spending for a household your size. This comparison uses the most recent BLS data available (typically 1–2 years behind current year).

The BLS comparison is informational, not prescriptive. Your household may spend more or less than average for valid reasons: location, preferences, life stage, or necessities the average does not capture. The comparison is a reference point, not a target.

What Per Year does not do

Per Year does not estimate or predict costs. It does not connect to your bank, scrape receipts, or infer bills from transaction history. Every number is typed by you and calculated with fixed arithmetic.

It does not use AI or machine learning. The Scenario Lab in the one-time plan report models hypothetical changes (like canceling a bill or switching to a cheaper plan), but those scenarios are arithmetic too: the tool recalculates your total with the changed bill and shows the year-over-year difference. No predictions, just deterministic what-if math.

It does not give financial advice. Per Year shows you the math and lets you decide what to do with it.

Why this matters

Most household budgeting tools hide their methodology or rely on statistical averages that may not match your life. Per Year shows its work. Every calculation is visible, every multiplier is explained, and you can verify the output yourself with a calculator if you want to.

This transparency means you can trust the numbers. If the yearly total is higher than you expected, it's not because the tool inflated anything—it's because the bills you entered, multiplied honestly over 12 months or 52 weeks, add up to that total. That clarity helps you make decisions instead of questioning the tool.