The HSE Tools

Man-Days Worked Calculator

Methodology & Standards

Calculations follow commonly used HSE practices. Always confirm with your organization’s definitions and local regulations. References: OSHA 1904, ISO 45001, ILO OSH.

Man-Days Worked Calculator

Project Inputs

Fill details, apply a template, preview, and export to PDF.

Project / Site Details

Workforce & Days

Category / Crew # Workers/Day Days Worked Shifts/Day Remove

Man-Days = # Workers/Day × Days Worked × Shifts/Day

Templates

Templates auto-fill project info + workforce rows.

Notes & Carry-Over

Actions

Use Shifts/Day > 1 for day+night operations.

Man-Days Worked Report

Generated preview — review and export to PDF

Generated On

Project / Site:

Client:

Location:

Period:

Report Type: Man-Days Worked

Workforce & Man-Days Summary

Category / Crew # Workers/Day Days Worked Shifts/Day Man-Days
Subtotal (This Period) 0

Man-Days (This Period)

0

Carry-Over (Before Period)

0

Cumulative Man-Days

0

Milestones

    Highlights / Remarks

    👷‍♂️ Man-Days Worked Calculator – Complete Guide

    Tracking man-days (and optional man-hours) is a cornerstone of HSE and project reporting. Accurate figures drive productivity metrics, cost control, and lagging/leading safety indicators (e.g., TRIR per 200k hours). This Man-Days Worked Calculator helps you compute headcount totals, man-days, and (if set) man-hours—then export a clean A4 PDF for records and audits.


    ✅ What Is a Man-Days Worked Calculator?

    A simple, structured tool that converts crew numbers and working days into report-ready totals. It avoids spreadsheet errors, standardizes the method, and produces a tidy PDF attachment for daily/weekly HSE reports.

    It typically includes:

    • Crew inputs (Skilled, Unskilled, Contract).
    • Period inputs (Days) and optional Hours/Day.
    • Auto-computed Headcount, Man-Days, Man-Hours.
    • PDF export for documentation.

    Note: Some clients define man-hours differently (e.g., exclude overtime). Always follow your contract/HSE procedure.


    🧮 Core Formulas (Standard)

    • Headcount = Skilled + Unskilled + Contract
    • Man-Days = Headcount × Days
    • Man-Hours = Man-Days × Hours/Day (optional—only if you provide Hours/Day)

    If your site uses a different basis (e.g., per shift or excludes certain categories), customize inputs accordingly.


    📋 Key Components of the Calculator

    • Inputs
      • Skilled, Unskilled, Contract (whole numbers ≥ 0)
      • Days (≥ 1)
      • Hours/Day (optional; whole or decimal, e.g., 8 or 8.5)
      • Project/Site (optional tag for the PDF)
    • Outputs
      • Crew tiles (Skilled, Unskilled, Contract, Headcount)
      • Period & totals (Days, Man-Days, Man-Hours)
      • Notes about how hours were computed
    • Actions
      • Calculate → updates results live
      • Download PDF → tidy A4 report (great for email to client/PM/HSE)
      • Reset → clears inputs & outputs
    • Validation
      • Ensures numeric fields are valid (e.g., Days ≥ 1, non-negative integers for crew)
      • Hours/Day can be blank (then man-hours are not calculated)

    🛠 How to Use the Man-Days Worked Calculator

    1. Enter Crew Counts — Skilled, Unskilled, Contract.
    2. Set Period Days — e.g., 26 for a 26-day month segment.
    3. (Optional) Hours/Day — e.g., 8 (or 10 for shutdowns). Leave blank to skip man-hours.
    4. Click Calculate — view Headcount, Man-Days, and Man-Hours (if Hours/Day provided).
    5. Download PDF — archive with your HSE pack / send to the client.
    6. Reset — clear inputs for the next period/site.

    Tip: Keep Hours/Day at your standard (often 8) and track overtime separately in your daily safety report.


    🧑‍🏫 Worked Examples

    Example 1 – Construction Project (Standard 8-hour day)

    • Skilled = 45, Unskilled = 60, Contract = 20 → Headcount = 125
    • Days = 26 → Man-Days = 125 × 26 = 3,250
    • Hours/Day = 8 → Man-Hours = 3,250 × 8 = 26,000

    Example 2 – Shutdown (10-hour day)

    • Skilled = 80, Unskilled = 120, Contract = 50 → Headcount = 250
    • Days = 12 → Man-Days = 3,000
    • Hours/Day = 10 → Man-Hours = 30,000

    Example 3 – Training Day (Count but no hours)

    • Skilled = 20, Unskilled = 0, Contract = 0 → Headcount = 20
    • Days = 1 → Man-Days = 20
    • Hours/Day left blank → Man-Hours = — (not computed)

    📌 Why This Matters for HSE & PMO

    • Accurate KPIs → TRIR, LTIFR, and productivity metrics rely on correct hours.
    • Budget & Cost Control → Man-hours drive labor cost and variance analysis.
    • Audit Readiness → PDF output serves as a quick record for client/ISO audits.
    • Consistency → Standardizes calculations across sites/contractors.

    🔍 Common Pitfalls (and Fixes)

    • Counting Absentees: Make sure crew numbers reflect actual presence, not roster.
    • Double-Counting Contractors: Confirm your definition (external vs. included in skilled/unskilled).
    • Inflated Hours: Don’t multiply by OT unless that’s your site’s official convention.
    • Missing Days Validation: The tool enforces Days ≥ 1 to avoid zeros.

    🌟 Best Practices

    • Align Hours/Day with your HSE manual (e.g., 8 hr standard + OT in separate line).
    • Use the Project/Site field to label your PDF per location or client.
    • Attach the PDF to your Daily Safety Report or Weekly KPI Pack.
    • Keep a consistent approach month-to-month for trend reliability.

    ❓ Frequently Asked Questions

    Can I leave Hours/Day blank?
    Yes. The tool will compute Man-Days and skip Man-Hours.

    Do visitors count?
    Typically no—unless they’re working hours under your scope. Follow your HSE procedure.

    Can I export multiple sites?
    Generate a separate PDF per site/period for clean traceability.

    Do absentees get counted in crew totals?
    No—use actual present headcount for the period.

    Are contractors counted separately from skilled/unskilled?
    Use your site convention. Either list contractors separately or include them in skilled/unskilled—just be consistent.


    🎯 Final Thoughts

    The Man-Days Worked Calculator brings clarity to crew reporting, reduces human error, and produces audit-friendly PDFs in seconds. Use it alongside your Daily Safety Report and Toolbox Talk/Training records for a complete, defensible HSE dossier.

    Next up: pair this with your Daily Safety Report Generator to keep headcount, activities, and hours consistent across all reports.

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