Methodology: PTO Accrual Calculator by State

What the calculator computes

The calculator takes four inputs — state, number of employees, hours per week, and weeks to project — and produces two outputs: a projected leave balance at the end of the period, and the per-state rules that produced that projection.

The math is straightforward. For each hour the employee works, they earn a fraction of an hour of leave — 1/30, 1/40, 1/35, or 1/52, depending on the state's statutory accrual rate. That fraction multiplied by the projected hours gives the accrued total. If the jurisdiction caps the balance, the projection caps with it.

What the projection assumes

The projection makes several simplifying assumptions about the employee and the employer. None of them are exposed as inputs.

• The employee starts with a zero leave balance — no carryover from prior years.
• The employee uses no leave during the projection period.
• The employer accrues rules-based, not frontload — no "grant the full annual amount upfront" mode.
• The employee works a constant weekly schedule (no variation).
• The employee is continuously employed (no leaves of absence, terminations, or gaps).
• Accrual begins on day one. Statutory waiting periods (California Labor Code §246(c) requires 90 days; Maine, Michigan, New Jersey, and Connecticut require 120) are shown but don't reduce the projected balance — they delay the USE of accrued leave, not its accumulation.

A worked example

A California employee working 40 hours per week for 52 weeks accrues at the state's statutory rate of 1 hour per 30 worked. The math: 40 ÷ 30 = 1.33 hours per week × 52 weeks = 69.3 hours, well under California's 80-hour balance cap.

The same schedule in Washington, where the rate is 1 per 40 and there is no statutory balance cap, yields 40 ÷ 40 × 52 = 52 hours that grows without limit as long as employment continues.

For a part-time employee working 20 hours per week the projection scales linearly: 20 ÷ 30 × 52 = 34.7 hours in California; 20 ÷ 40 × 52 = 26 hours in Washington. The accrual rate is per-hour-worked, not per-week — half-time hours produce half the leave.

What's modeled

20 jurisdictions: 18 US states with paid-sick-leave laws, Nebraska's Healthy Families and Workplaces Act (effective October 1, 2025), and the New York City and San Francisco ordinances (which override their state's rules).

Six jurisdictions have two-tier rules that switch on employer headcount — Alaska (threshold 15), Arizona (15), Michigan (11), Nebraska (20), New York City (100), and San Francisco (10). The "Employees" input picks the correct tier.

What's not modeled (and why)

Three-tier ordinances. Chicago, Seattle (1-49 / 50-249 / 250+ FTEs), and Washington DC (1-24 / 25-99 / 100+) each use three tiers with different accrual rates AND different caps per tier. They need a data shape the current model doesn't support, so they're deferred until a future iteration.

Unpaid-leave carve-outs. Maryland's Healthy Working Families Act applies to employers with 15+ employees as paid leave; under 15 it requires unpaid leave. Massachusetts (G.L. c. 149 §148C) has the same shape at an 11-employee threshold. The calculator shows both as paid coverage at any size; the result is approximate for those small-employer cases.

Coverage floors. Nevada's statute (NRS §608.0197) applies only to employers with 50 or more employees; Nebraska's only to 11 or more. Below those thresholds the laws don't apply at all — but the calculator shows them as covered regardless, with a note in the rule details.

Phase-ins by year. Connecticut's law (CGS §31-57v) phases in by employer size on a yearly schedule: 25+ employees in 2025, 11+ in 2026, all employers in 2027. The calculator uses the fully-rolled-out rules.

Recent legislative churn. Michigan's Earned Sick Time Act was substantially amended in February 2025 — large employers may now cap accrual / carryover / usage at 72 hours where formerly accrual caps were prohibited entirely. The calculator reflects the post-amendment rules. Missouri's Prop A took effect May 2025 and was repealed by HB 567 in August 2025; no Missouri law is in force currently.

Data sources

Per-state rules are derived from the Paid Sick Leave Laws by State article, which is itself grounded in state department-of-labor pages and statute text. Statute text for load-bearing citations: California Labor Code §246, Washington RCW 49.46.210, Connecticut CGS §31-57v, and New Mexico Healthy Workplaces Act (NMSA Chapter 50, Article 17). Primary sources verified during the most recent fact-check include the California DIR Paid Sick Leave FAQ, Washington L&I Paid Sick Leave Requirements, NYC DCWP ESSTA, Maryland DOL Paid Leave FAQ, and Nebraska DOL Paid Sick Time FAQ.

When a state law changes, both this tool's data file and the companion article are updated in the same commit.

How accurate is this?

Accurate enough for orientation, not for payroll. Real payroll math involves things this calculator doesn't model: variable hours, leaves of absence, mid-period employer policy changes, frontload toggles, multi-state employment, and dozens of small statutory carve-outs. A calculator that handled all of that would need fifteen inputs and most visitors would bounce before submitting.

This tool is built to answer the typical query — "roughly how much PTO do I accrue working full-time in [state]?" — well enough for a quick check. For precise per-employee balance tracking, that's what payroll software is for.