# Shift Relief Factor and FTE Coverage Calculator

> Source: https://netray.co/tools/shift-relief-factor-fte-coverage-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Calculates the relief factor and the number of employees needed to staff continuously operated posts after paid leave and training time.

## Category

ehs-workforce

## Industry

Discrete Manufacturing

## Audience

- Plant HR
- Production supervisor
- Operations manager

## Tool

**Kind:** calculator

**Currency:** $

**Inputs:**

#### Posts staffed at all times

**Key:** posts

**Type:** number

**Default:** 5

**Min:** 1

**Step:** 1

**Unit:** posts

**Help:** Stations or roles that must be covered every hour of operation.

#### Operating hours per week

**Key:** op_hours

**Type:** number

**Default:** 168

**Min:** 8

**Max:** 168

**Step:** 8

**Unit:** h

**Help:** 168 for 24/7 operations, 120 for 24/5, 80 for two shifts of 5 days.

#### Weeks operating per year

**Key:** weeks

**Type:** number

**Default:** 52

**Min:** 1

**Max:** 52

**Step:** 1

**Unit:** weeks

#### Paid hours per employee per week

**Key:** week_hours

**Type:** number

**Default:** 40

**Min:** 1

**Step:** 1

**Unit:** h

#### Vacation days per employee

**Key:** vacation

**Type:** number

**Default:** 15

**Min:** 0

**Step:** 1

**Unit:** days

#### Paid holidays not worked

**Key:** holidays

**Type:** number

**Default:** 8

**Min:** 0

**Step:** 1

**Unit:** days

#### Sick and other absence days

**Key:** sick

**Type:** number

**Default:** 6

**Min:** 0

**Step:** 1

**Unit:** days

#### Training and meeting hours per year

**Key:** training

**Type:** number

**Default:** 24

**Min:** 0

**Step:** 2

**Unit:** h

#### Shift length

**Key:** shift_len

**Type:** select

**Default:** 8

**Options:**

##### 8 hours

**Value:** 8

##### 10 hours

**Value:** 10

##### 12 hours

**Value:** 12

#### Annual loaded cost per employee

**Key:** cost

**Type:** number

**Default:** 68000

**Min:** 0

**Step:** 1000

**Unit:** $

**Outputs:**

#### Hours to cover per post per year

**Key:** post_hours

**Expr:** op_hours * weeks

**Format:** number

#### Paid hours per employee per year

**Key:** paid

**Expr:** week_hours * 52

**Format:** number

#### Productive hours per employee

**Key:** productive

**Expr:** paid - (vacation + holidays + sick) * shift_len - training

**Format:** number

#### Relief factor

**Key:** relief

**Expr:** post_hours / productive

**Format:** decimal

**Primary:** true

#### Employees needed (unrounded)

**Key:** fte

**Expr:** posts * relief

**Format:** decimal

#### Employees to hire or assign

**Key:** heads

**Expr:** ceil(fte)

**Format:** integer

**Primary:** true

#### Availability of a paid hour

**Key:** avail

**Expr:** productive / paid * 100

**Format:** percent

#### Annual cost of this crew

**Key:** annual

**Expr:** heads * cost

**Format:** currency

**Chart:**

#### Employees needed vs vacation days

**Type:** line

**X:** vacation

**From:** 0

**To:** 30

**Steps:** 16

**Series:**

- heads

**Disclaimer:** Assumes absence days are fully backfilled by the crew and ignores overtime, floaters and part-time staff.

## Content

**Intro:** A post that must be staffed around the clock needs far more than one employee per shift. The relief factor is the multiplier that turns posts into heads after leave, holidays and training.

**Sections:**

#### How to use it

**Body:** Enter the number of posts that must be staffed at all times and how many hours per week the plant runs. Add the paid hours per employee per week and the average days of vacation, holidays, sick leave and training they take. Choose the shift length so days convert to hours correctly. The result shows the relief factor, the number of employees needed and the annual cost.

**Bullets:**

- Use actual absence history, not policy maximums
- Run the model separately for 12-hour shift crews and 8-hour crews
- Include leave of absence and long-term injury if material

#### Formula

**Body:** Relief factor equals the hours a post must be covered per year divided by the productive hours one employee delivers per year. Productive hours are paid hours less leave hours and training hours. For a 24/7 post that is 8,736 hours, and with about 1,800 productive hours per employee the factor is near 4.8, so one post needs nearly five people. Multiply by posts and round up to get heads.

#### Reading the result

**Body:** The relief factor is the number every shift manager should know. A factor lower than expected usually means leave is under-estimated. Use the chart to see how vacation days change headcount, which helps in policy discussions. Where the rounded head count is above the unrounded figure by a large amount, part-time or floater coverage may be cheaper than a full extra position.

#### Common mistakes

**Body:** Do not divide 168 hours by 40 and call it 4.2 people, since that ignores all leave. Do not mix shift lengths without adjusting days to hours, because a 12-hour shift day removes 12 hours of availability. Finally, if you run overtime to cover leave, the cost will differ from this model, so compare it with the overtime versus added shift calculator.

**Cta:** If you want absence, leave and overtime data pulled from payroll and the ERP to calibrate this model, we can build that report for your plant.

**Faq:**

#### What is a relief factor?

**Answer:** It is the ratio of the hours a position must be covered to the productive hours one employee provides. A factor of 4.8 means one continuously staffed post requires 4.8 full-time employees once leave and training are considered.

#### Why is the answer different for 12-hour shifts?

**Answer:** A leave day removes more hours on a 12-hour crew. Set the shift length input to match so that vacation, holiday and sick days convert to the correct hours. Paid hours per week may also differ for rotating patterns.

#### Does this work for 4 on 4 off or 2-2-3 patterns?

**Answer:** Yes for the totals, because it works from annual hours covered and annual hours delivered. It does not build the roster itself. Use a schedule template to check that the pattern gives enough crews on each day.

#### Should I include absenteeism beyond sick days?

**Answer:** Yes. Add unpaid absences, leave of absence and long-term disability in the absence days input if they are not backfilled elsewhere. Using last year's actual total from HR is more accurate than a policy figure.

## Search terms

relief factor calculator, shift relief factor, fte per post calculator, 24/7 staffing calculator, how many employees to cover a shift, staffing coverage factor, post coverage calculation, shift staffing formula

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