Examples
Worked examples
- Is an instance
A university proposes 6 person-months of a postdoctoral researcher's time on Work Package 3 over a 24-month project — this is stated in the proposal's Gantt/effort table and used to size the requested personnel budget, using the 220-days-per-year planning conversion (6 person-months ≈ 110 working days).
- Is an instance
At reporting time, the same researcher actually worked 95 days on the action during the relevant period. Personnel costs are calculated as: (annual personnel costs ÷ number of actual annual working hours or the 215-day standard, per the beneficiary's chosen costing methodology) × number of hours or days worked on the action × hourly/daily rate — not by simply re-applying the proposal's 6-person-month planning figure.
- Is an instance
A beneficiary using Horizon Europe's average personnel cost (unit-cost) methodology reports personnel time in hours worked on the action multiplied by a Commission-accepted average hourly rate, sidestepping day-based actual-cost calculation entirely, though the proposal-stage person-months figure is still used for work-plan and budget-sizing purposes.
Counter-examples
Looks similar, but isn't
- Not an instance
Applying NIH's person-months formula (percent effort × months in a CY/AY/SM appointment type) to a Horizon Europe budget or reporting table is a mismatch: Horizon Europe ties personnel reporting to actual days or hours worked against a capped annual standard (215 days, or actual annual productive/workable hours), not to a percentage of a US-style calendar-year, academic-year, or summer appointment — the two funders' effort-reporting logics are structurally different even though both use the term 'person-months.'
- Not an instance
Treating the 220-day planning conversion as the figure used for actual-cost reporting is incorrect — 220 days/year is an indicative estimation aid for the proposal phase only; the Annotated Model Grant Agreement's operative ceiling for actual personnel-cost reporting is 215 days/year.
Editorial commentary
Research administrators moving between US federal grants and EU Horizon Europe awards frequently assume “person months” means the same thing in both systems because the term is identical. It does not. This entry covers the Horizon Europe-specific methodology; for NIH’s percent-effort/appointment-type methodology, see the dedicated Person Months (NIH) entry.
Why Horizon Europe uses person-months at the proposal stage
Every Horizon Europe proposal’s work plan (the Gantt chart and the accompanying Table 3.1 effort summary) requires each beneficiary to state, per work package, how many person-months of staff time it is committing. Evaluators use this to sanity-check that the proposed effort is proportionate to the requested budget and the work described. Because proposals are drafted before the actual costing methodology is applied at reporting, the Commission provides an indicative conversion — 220 working days per year equal 12 person-months — purely as a planning aid, not a costing rule.
Why actual-cost reporting does not use the same figure
Personnel costs actually charged to the action are calculated under Article 6.2.A of the Horizon Europe Annotated Model Grant Agreement (AGA) using an hourly-rate or daily-rate methodology grounded in the beneficiary’s usual cost-accounting practices, subject to a hard ceiling: the standard number of working days used to compute the maximum declarable day-equivalents for a reporting period is 215 days per year. The maximum a beneficiary may declare is (215 ÷ 12) × the number of months in the reporting period, further pro-rated by the individual’s working-time (FTE) factor if they work part time. This is a ceiling on what can be charged, not an entitlement to that many days — actual days or hours genuinely worked on the action are what gets reported and paid.
Beneficiaries may instead elect the Commission’s average personnel cost option (a Commission-accepted unit cost per hour, calculated from the organisation’s own historical personnel cost data), in which case personnel time is reported in hours actually worked on the action rather than days, and the 215-day ceiling logic does not directly apply in the same way.
Lump-sum grants: a separate case
An increasing share of Horizon Europe calls (particularly Pillar II collaborative projects) are funded as lump-sum grants, where beneficiaries are paid a fixed amount per work package on completion of agreed deliverables rather than on actual costs. Person-months are still used in the proposal’s work plan for planning and evaluation purposes under a lump-sum grant, but there is no actual-cost personnel reporting at all during the project — the 215-day ceiling and hourly/daily-rate calculations described above are specific to actual-cost (non-lump-sum) grant agreements.
How this differs from NIH’s methodology
NIH’s person-months figure is a direct product of percent effort committed and the length of the person’s formal appointment type — calendar year (12 months), academic year (institution-defined, commonly 9), or summer term (institution-defined, commonly 2–3 months) — with no separate day-count ceiling in the formula itself. Horizon Europe’s figure is, by contrast, downstream of actual days or hours worked against a capped annual standard, and the person-months figure quoted in a proposal is explicitly a planning estimate rather than the number directly reconciled against costs at reporting. A research administrator supporting a researcher with both an NIH award and a Horizon Europe grant should not carry an effort-reporting spreadsheet or formula built for one funder over to the other without adjustment. See also the related Horizon Europe budgeting terms below for how person-months feeds into the broader grant-agreement structure.
Related terms
- Person Months (NIH) — the CY/AY/SM percent-effort methodology this entry is distinguished from.
- Grant Agreement (Horizon Europe)
- Work package (Horizon Europe)
- Task (Horizon Europe)
- Lump-sum grant (Horizon Europe)
- Beneficiary (Horizon Europe)
- Indirect Cost Rate Proposal
Frequently asked questions
How do you calculate person-months for a Horizon Europe proposal?
At proposal stage, use the Commission’s indicative planning conversion of 220 working days per year to 12 person-months (roughly 18.3 working days per person-month) to translate the staff time you’re committing per work package into a person-months figure for the Gantt chart and effort table.
Is the Horizon Europe person-months formula the same as NIH’s?
No. NIH multiplies percent effort by the number of months in a person’s calendar-year, academic-year, or summer appointment. Horizon Europe’s actual-cost reporting instead caps declarable time at 215 working days per year (pro-rated for the reporting period and any part-time factor), with the proposal-stage person-months figure serving only as a planning estimate.
Does a lump-sum Horizon Europe grant still use person-months?
Yes, in the proposal’s work plan for planning and evaluation, but there is no actual personnel-cost reporting against a person-months or day-based figure once the grant is awarded as lump-sum — payment is deliverable-based.
Machine-readable encodings
Use in your systems
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"description": "<p>In <strong>Horizon Europe</strong>, a person-month is the unit used in a proposal's work plan (Gantt chart and effort tables) to show how much staff time each beneficiary allocates to a work package or task. It is an <em>estimation and planning</em> unit, not the basis the European Commission actually pays on — that is a distinct point of confusion with NIH's identically-named unit. Actual personnel costs at reporting time are calculated in <strong>person-days</strong> against a capped standard number of working days per year, not directly in person-months, and beneficiaries using the Commission's average personnel cost (unit-cost) option may not need to track individual days at all.</p><p>The European Commission's own indicative conversion, used for translating between days and months at proposal stage, is <strong>220 working days per year = 12 person-months</strong> (so 1 person-month ≈ 18.3 working days). This 220-day planning figure is different from the <strong>215 working days per year</strong> figure that is the operative ceiling for <em>actual-cost</em> personnel reporting under the Horizon Europe Annotated Model Grant Agreement (AGA), Article 6.2.A — the maximum number of day-equivalents a beneficiary may charge to the action in a given period is calculated as (215 ÷ 12) × number of months in the reporting period, pro-rated by a working-time (FTE) factor for part-time staff. The 220 and 215 figures serve different purposes (proposal planning vs. reporting ceiling) and should not be interchanged.</p>",
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