Military Leave Accrual Calculator

Understanding military leave accrual, the 60-day cap, and use-or-lose days

Introduction: how active-duty leave really adds up

Every member of the armed forces earns leave at 2.5 calendar days per month of active service, 30 days per year, under 10 U.S.C. 701 and DoD Instruction 1327.06. Leave accrues in every duty status that counts as active service, including while you are deployed, on TDY, or already on leave; it stops only for AWOL, excess leave, and confinement under a court-martial sentence. Because leave accounting runs on the federal fiscal year and the pay system drops days above your carryover cap every 1 October, the balance question that matters is rarely “how much have I earned?” but “how much will I have on 30 September, and how much of it is use-or-lose?”

This calculator answers both. It credits leave month by month using the official partial-month bands from the service leave regulations, reconstructs your balance on any as-of date, projects the remaining accrual to 30 September, and flags the days you must take before fiscal-year end. Knowing those numbers early helps you:

• Plan block leave, holiday travel, and family events around the fiscal-year cutoff
• Schedule PCS moves and long schools without stranding days above the cap
• Decide when a special leave accrual (SLA) request or a sell-back conversation is worth having

The formula and the official partial-month bands

Most unofficial leave tools divide the days you served by an average month length such as 30.4375 and multiply by 2.5. The pay system does not work that way. The Defense Joint Military Pay System credits leave in half-day bands of six days: the accrual tables in DAFI 36-3003 (Tables 2.1 and 2.2), AR 600-8-10, and MILPERSMAN all credit 0.5 days once a partial month reaches day 1–6, 1.0 day at day 7–12, and so on up to the full 2.5 at day 25 or later. Averaging month lengths can drift a fraction of a day from the official answer; the bands reproduce it exactly.

Both columns come from a single crediting function. Let f(d) be the leave credited through day d of a month:

A month in which you serve from day a through day b credits f(b) − f(a) + 0.5 days: a full month credits the familiar 2.5, an entry month reproduces the left column of the table above, and a final month reproduces the right column. Summing over every calendar month in your period gives leave earned E, and the balance follows:

where C is the balance carried into the start date, E is leave earned through the as-of date, and U is chargeable leave used. The projection extends the same crediting to 30 September, subtracts planned leave, and compares against the cap.

Plain-text formula: f(d) = min(2.5, 0.5 × ceil(d ÷ 6)); monthCredit = f(lastDayServed) − f(firstDayServed) + 0.5; earned = sum of monthCredit over each calendar month; balance = carryover + earned − used; futureAccrual = earnedThroughSep30 − earnedThroughAsOf, so no month is ever credited twice; projectedSep30 = balance + futureAccrual − plannedLeave; useOrLose = max(0, projectedSep30 − cap).

Source/version metadata: accrual rate and fiscal-year balancing per 10 U.S.C. 701 and DoD Instruction 1327.06; partial-month bands per DAFI 36-3003 Tables 2.1–2.2 and equivalent Army/Navy tables; SLA ceiling of 90 days per section 632 of the FY2023 NDAA; last reviewed July 2026. This is an unofficial planning estimate: verify balances on your LES and with your finance office.

Fiscal-year balancing on 30 September and use-or-lose leave

Military leave follows the federal fiscal year, 1 October through 30 September. At fiscal-year-end balancing, the pay system carries forward at most your cap, 60 days for most members, and drops the rest. Days projected to sit above the cap on 30 September are use-or-lose: they must be taken as chargeable leave before the cutoff or they vanish on 1 October. Lost leave can be restored only in narrow circumstances (for example, leave properly requested and cancelled for military necessity, pursued through a correction-of-records request), so the practical answer is to see the problem months early.

A concrete case: you start the fiscal year on 1 October with 58 days carried over, and by 15 March you have used only 4 days. The bands credit 14.0 days from 1 October through 15 March (five full months plus 1.5 for mid-March), putting you at 68.0. Another 16.0 days accrue by 30 September, so even after 10 days of planned summer leave you project 74.0, which is 14.0 days above a 60-day cap. Spread over the roughly six and a half months remaining, that is about two extra days of leave to schedule per month, an easy fix in March and a painful one in September.

Special leave accrual after the FY2023 NDAA: the 90-day ceiling

Members whose deployments or assignments prevent taking leave can request special leave accrual. SLA typically requires at least 120 consecutive days in a hostile-fire or imminent-danger pay area, or other qualifying duty designated by the service. Two rules changed with section 632 of the FY2023 National Defense Authorization Act, effective in fiscal year 2023:

• The SLA ceiling dropped from 120 to 90 days of total accumulated leave.
• Protected days above 60 generally must be used within two fiscal years after the fiscal year in which the qualifying service ends (previously three).

SLA is not automatic: it must be documented through your service’s process, and protected days are tracked separately on the LES. If you believe SLA applies, select the 90-day cap here for planning, then confirm the coding with your unit admin or finance office before relying on it. The DoD announcement of the SLA changes summarizes the transition rules for balances accrued before 2023.

Sample accrual milestones

With continuous service and no leave taken, the 2.5-days-per-month rate compounds quickly. Two years of saved accrual alone fills the standard 60-day carryover cap.

Worked example: nine months of service with carryover

Scenario: your accrual period runs from 1 January through an as-of date of 30 September of the same year. You carried 5 days into the period and have used 10 days of chargeable leave.

1. Credit each month with the bands. January through September are all full months, and a full month always credits 2.5 days, so leave earned is E = 9 × 2.5 = 22.5 days.
2. Apply the balance formula. L = C + E − U = 5 + 22.5 − 10 = 17.5 days.
3. Project to fiscal-year end. The as-of date is already 30 September, so no further accrual applies: the projected 30 September balance is 17.5 days, well under a 60-day cap, with 0.0 use-or-lose days.

Enter those inputs above and the calculator reports exactly 22.5 days earned and a 17.5-day balance. That exactness is the point: a tool that averages month lengths shows about 17.3 days for this scenario, and while a fraction of a day sounds harmless, banded crediting is the difference between matching your LES and explaining away drift.

Comparison: this estimate versus your official LES

How to use this military leave calculator

Two setups cover most planning questions:

• Fiscal-year planning (default): keep the pre-filled start of 1 October, enter the BF BAL (brought-forward balance) from your first LES of the fiscal year as the carried-in balance, and enter chargeable days used since 1 October. The projection then mirrors what DJMS will do at balancing.
• Full-period reconstruction: set the start date to your active-duty start (or any date you knew your balance), enter that balance as carried-in, and the calculator rebuilds earned leave from there.

Add any leave you already plan to take before 30 September, pick the cap (60 standard, 90 with approved SLA, or a custom value), and calculate. The results show leave earned, your as-of balance, the projected 30 September balance, and use-or-lose days; the chart and month-by-month schedule show when the balance crosses the cap, and the copy and CSV buttons export the projection for a leave-planning conversation with your supervisor. When separation or retirement is on the horizon, continue with the companion military leave sell-back and terminal leave calculator, and if a reenlistment decision is in play, the selective reenlistment bonus calculator pairs well with it. Federal civilians should use the federal employee leave accrual and payout calculator instead, since civilian rules differ completely.

Assumptions and limitations of this leave model

• Continuous accrual assumed. Every day between your dates is treated as leave-earning active service. AWOL, excess leave, confinement, and broken service are not modeled.
• One usage total. Leave used is entered as a single total of chargeable days, and the schedule applies it in the month containing the as-of date; the real timing of past leave does not change the final balance, but it does change mid-period rows.
• Planned leave is spread evenly. Future planned days are distributed across the remaining months of the fiscal year for charting; your actual leave dates will shape the curve differently.
• Caps are applied only at 30 September. The tool compares the projected balance to one cap value. It does not age individual SLA days, model their expiration dates, or apply the career 60-day sell-back cap.
• Reserve component nuance. The model fits continuous active duty (including AGR). Drilling Guard and Reserve members accrue only during active-duty periods, so enter each active period separately.
• Unofficial estimate. The LES and your finance office are the only authoritative sources; use this page to plan, not to certify.

Military leave accrual: frequently asked questions