Measuring Volunteer Impact: Metrics That Actually Matter
"We had 500 volunteers" is a vanity metric. Here's how to measure what really matters—and tell stories that move your board, funders, and community.
The Measurement Problem
Most charities measure volunteers the wrong way. They count heads and hours, then wonder why their board isn't impressed and funders want more detail.
Headcount is not impact. 500 volunteers who showed up once is very different from 200 volunteers who came back month after month. 10,000 hours of effort that didn't move the needle is less valuable than 1,000 hours that changed lives.
The right metrics tell you whether your volunteer programme is healthy, efficient, and actually achieving your mission. Here's what to track—and why it matters.
Quick Diagnostic: How Healthy Is Your Volunteer Programme?
If you don't know these numbers, you're flying blind
What's your volunteer retention rate?
60%+ is healthy
What's your no-show rate?
Under 15% is good
How much is your volunteer time worth?
NZ: $33.50/hr × hours
Would volunteers recommend you?
NPS 50+ is excellent
The Metrics That Matter
Four categories of metrics give you a complete picture of your volunteer programme
Engagement Metrics
Are volunteers showing up and coming back?
Volunteer Retention Rate
60-70%
Top programmes
What percentage of volunteers return for a second shift? Third? This is your single most important metric for volunteer programme health.
Formula
(Returning Volunteers / Total Volunteers) × 100
One charity discovered their retention rate was just 23%. After investigating, they found volunteers weren't receiving shift confirmations. A simple automated email lifted retention to 61%.
Below 40% signals something is broken in your volunteer experience.
No-Show Rate
<15%
Healthy
What percentage of registered volunteers don't show up? High no-show rates indicate problems with your communication, reminder system, or volunteer experience.
Formula
(No-Shows / Total Registered) × 100
A street appeal organisers saw 35% no-shows. They added text reminders 24 hours and 2 hours before shifts—no-shows dropped to 12%.
Above 25% means you're planning around unreliable numbers.
Shift Fill Rate
90%+
For events
What percentage of available shifts are filled? This tells you if you have enough volunteer supply to meet demand.
Formula
(Filled Shifts / Available Shifts) × 100
A festival consistently filled 95% of shifts by offering flexible 2-hour blocks instead of full-day commitments.
Below 80% means gaps are affecting your operations.
Impact Metrics
What difference are volunteers making?
Hours Contributed
Varies
By org size
Total volunteer hours is a foundation metric, but it's most useful when connected to outcomes. Track hours by activity type to understand where effort is going.
Formula
Sum of all volunteer hours
Assistance Dogs NZ tracks hours by activity: puppy raising, events, admin. They discovered 40% of hours went to fundraising—informing their strategy.
Tip: Don't just count hours—categorise them to spot where effort concentrates.
Value of Volunteer Time
NZ: $33.50/hr
AU: $49.50/hr
Converting hours to dollar value helps communicate impact to boards and funders. Use your country's standard volunteer hour rate.
Formula
Total Hours × Hourly Rate
A small charity with 2,000 volunteer hours annually realised that represented $67,000 of in-kind support—transforming how their board viewed the volunteer programme.
Tip: Include this figure in funding applications as 'in-kind contribution'.
Beneficiaries Served
Track trend
Over time
How many people did your volunteers help? This connects volunteer effort to mission outcomes in a tangible way.
Formula
Count of people served
'Our 50 volunteers served 1,200 meals this month' is infinitely more powerful than 'we had 50 volunteers'.
Tip: Find your 'unit of impact'—meals, families, hours of care, dogs trained.
Operational Metrics
How efficient is your volunteer programme?
Time to Fill
Varies
By role
How long does it take to fill volunteer positions after posting? Longer times indicate recruitment or positioning issues.
Formula
Days from posting to filled
One charity took 6 weeks to fill event roles. By listing on SEEK Volunteer and simplifying their sign-up, they cut it to 10 days.
Consistently long fill times mean your opportunities aren't reaching the right people.
Admin Time per Volunteer
Decreasing
With good systems
How much staff time does it take to manage each volunteer? This reveals operational efficiency and the ROI of your management tools.
Formula
Admin Hours / Volunteers
A coordinator spent 15 hours/week on spreadsheets and email. After implementing volunteer management software, that dropped to 3 hours.
Tip: Calculate this before and after any systems change to prove ROI.
Cost per Volunteer
Track trend
Year over year
Total programme costs divided by volunteers. Useful for understanding true programme efficiency and making budget decisions.
Formula
Programme Costs / Active Volunteers
A charity's cost-per-volunteer was $85. They realised most was printing. Going digital dropped it to $12.
Tip: Include staff time, software, training materials, recognition costs.
Satisfaction Metrics
Are volunteers happy?
Net Promoter Score (NPS)
50+
Excellent
Would volunteers recommend volunteering with you to others? This single question captures overall satisfaction and predicts retention.
Formula
% Promoters - % Detractors
A charity with NPS of 72 found their volunteers were actively recruiting friends. Word-of-mouth became their #1 recruitment channel.
Tip: Ask: 'How likely are you to recommend volunteering with us?' (0-10 scale)
Volunteer Satisfaction Score
4+
Out of 5
A broader survey measuring satisfaction with various aspects: training, communication, appreciation, and the work itself.
Formula
Average of satisfaction ratings
Surveys revealed volunteers loved the work but felt underappreciated. Monthly thank-you emails lifted satisfaction from 3.2 to 4.4.
Tip: Survey after first shift, then quarterly. Short surveys get more responses.
Reporting: Different Audiences, Different Stories
The same data tells different stories depending on who's listening
Your Board
They care about: Strategic value and ROI
Include:
- Dollar value of volunteer contributions
- Volunteer retention rate and trend
- Cost per volunteer (efficiency)
- Key outcomes tied to mission
Example statement:
"This year, 245 volunteers contributed 4,800 hours—worth $160,800 in services. Our 68% retention rate (up from 52%) means we're building a sustainable volunteer workforce."
Funders & Sponsors
They care about: Impact and accountability
Include:
- Beneficiaries served
- Outcomes achieved
- Volunteer hours by programme
- Stories alongside numbers
Example statement:
"Your funding supported 120 volunteer collection points, staffed by 380 volunteers who raised $127,000 for assistance dog training."
Volunteers Themselves
They care about: Their personal impact
Include:
- Collective achievements they contributed to
- Individual recognition
- Community impact stories
- Comparison to goals/targets
Example statement:
"Thanks to you and 89 other volunteers this month, 200 families received emergency food parcels. Your 6 hours made a real difference."
The Difference Measurement Makes
WITHOUT METRICS
- "We had lots of volunteers this year"
- "The event went well, I think"
- "People seem to enjoy volunteering with us"
- "We need more budget for volunteer coordination, probably"
- "The board doesn't really understand what we do"
WITH METRICS
- "245 volunteers contributed 4,800 hours worth $160,800"
- "We hit 94% shift fill rate with only 11% no-shows"
- "Our NPS of 68 shows volunteers actively recommend us"
- "New software cut admin time 80%, saving $15,000/year"
- "Volunteer retention increased from 42% to 67%"
Getting Started: Your First 30 Days
Week 1
Pick your 'vital few'—choose 3-4 metrics that matter most for your goals
Week 2
Establish baselines—what are your current numbers? (Even rough estimates help)
Week 3
Set up tracking—whether in a spreadsheet or software, create a simple dashboard
Week 4
Share with your team—make metrics visible and discuss what they mean
Ongoing
Review monthly, report quarterly, and tell stories alongside the numbers
Key Takeaways
Track what matters—automatically
PurposeTech gives you real-time dashboards with retention rates, no-show tracking, and impact metrics—no spreadsheets required.