Community Fridge Restocking and Spoilage Planner
The Community Fridge Restocking and Spoilage Planner helps mutual aid groups, neighborhood organizers, and food rescue volunteers sketch out a realistic plan for keeping a community fridge stocked, safe, and sustainable. By combining estimates of daily visitors, typical servings taken, donation sizes, cold storage capacity, and volunteer time, it offers a planning view of restocking cadence, likely spoilage, and workload.
How this planner works
This tool treats your community fridge as a simple system with food coming in during restock visits and food going out as visitors take servings. Food that stays in the fridge too long is gradually lost to spoilage. Refrigeration downtime makes that spoilage worse. The calculator uses your inputs to estimate whether your current restocking pattern is likely to:
- Leave the fridge empty before the next donation window (under-supply)
- Overflow capacity or create high spoilage risk (over-supply)
- Demand more volunteer minutes than your team can reasonably provide
Key formulas behind the estimates
At a high level, the planner looks at demand, supply, and spoilage over an average week:
- Daily demand (servings per day) = average daily visitors × average servings per visitor
- Weekly demand (servings per week) = daily demand × 7
- Weekly supply (servings per week) = donation size per restock × restock visits per week
- Volunteer time per week (minutes) = minutes per visit × restock visits per week
Spoilage is modeled as a percentage of whatever food remains at the end of each day. If your expected spoilage rate is s percent per day, and you start the day with F servings after visitors take what they need, the next day starts with:
Weekly refrigeration downtime (in hours) is used to increase effective spoilage. For example, if your fridge is typically off for 4 hours per week during hot weather, the tool can flag that as higher spoilage risk compared with a fridge that stays consistently cold.
Inputs overview
The form asks for a few practical estimates. If you do not know exact numbers, use your best recent averages or a short manual count over a few days.
- Average daily visitors – how many people take food from the fridge on a typical day.
- Average servings taken per visitor – a “serving” is roughly one meal-sized portion. If people usually take food for themselves and one other person, this might be 2–3 servings.
- Average donation size per restock (servings) – how many servings are added each time volunteers or partners restock the fridge.
- Scheduled restock visits per week – how many times per week the fridge is topped up according to your current plan.
- Cold storage capacity (servings) – roughly how many total servings fit safely in the fridge without over-packing or blocking airflow.
- Expected spoilage rate per day (% of remaining food) – the share of remaining food you expect to become unsafe or unusable each day.
- Weekly refrigeration downtime (hours) – typical hours per week the fridge is off, too warm, or without power.
- Volunteer minutes per restock visit – time needed for travel, sorting, cleaning, labeling, and restocking on a typical visit.
Interpreting the results
After you enter your numbers and run the planner, you will typically see information in three broad areas:
- Stock level balance – whether weekly supply roughly matches weekly demand. Large gaps suggest you may need bigger donations, more restocks, or fewer per-visit servings to keep things equitable.
- Spoilage and downtime risk – a qualitative tier (for example, low, moderate, or high risk) based on your daily spoilage rate and fridge downtime. High risk can signal the need for smaller, more frequent donations or better temperature control.
- Volunteer workload – an estimate of weekly volunteer minutes and whether that looks light, moderate, or heavy, given typical small mutual-aid teams.
Use these outputs as planning signals, not precise predictions. If the planner marks risk as “high” or workload as “heavy,” adjust your inputs to explore scenarios such as adding one more weekly restock, reducing donation size, or recruiting extra volunteers.
Worked example
Imagine an urban community fridge outside a busy transit stop. Organizers report:
- Average daily visitors: 95
- Average servings per visitor: 1.5
- Donation size per restock: 220 servings
- Restock visits per week: 5
- Cold storage capacity: 360 servings
- Expected spoilage rate: 6% per day
- Weekly refrigeration downtime: 4 hours
- Volunteer time: 40 minutes per visit
The planner estimates:
- Daily demand = 95 × 1.5 = 142.5 servings
- Weekly demand ≈ 998 servings
- Weekly supply = 220 × 5 = 1,100 servings
- Volunteer time per week = 40 × 5 = 200 minutes (over 3 hours)
Supply is slightly higher than demand, but a 6% daily spoilage rate, plus 4 hours of downtime, means a meaningful share of that surplus may be lost. The tool is likely to flag moderate to high spoilage risk and a moderate volunteer workload. In response, organizers might test either slightly smaller donations per restock (to reduce overflow and waste) or one additional volunteer per shift to make the workload easier to share.
Scenario comparison
The table below illustrates how changing restocking strategy can affect risk and workload. These are generic examples; your own results depend on your inputs.
| Scenario | Restocks / week | Donation size (servings) | Estimated spoilage risk | Volunteer load |
|---|---|---|---|---|
| Large, infrequent drops | 2 | 400 | High (often over capacity, longer time in fridge) | Light (fewer trips, but longer visits) |
| Balanced weekly plan | 4 | 220 | Medium (better flow, some surplus at week’s end) | Moderate (steady, predictable shifts) |
| Smaller, frequent top-ups | 7 | 140 | Low (less time in fridge, less overflow) | Heavy (more total trips to coordinate) |
Use the planner to experiment with your own versions of these scenarios and look for a combination that keeps risk acceptable while staying realistic for your volunteers.
Assumptions and limitations
To keep the tool simple and fast, several assumptions are baked into the calculations:
- Visitor numbers and servings per visitor are treated as relatively steady over the week.
- Spoilage is modeled as an average percentage of remaining food, not by specific food type.
- Refrigeration downtime is entered as total weekly hours, without distinguishing time of day or exact temperature.
- Donations are assumed to be spread evenly according to your restocking schedule, without last-minute surges or cancellations.
Limitations to keep in mind:
- The planner does not give food safety guarantees or replace local food safety guidance.
- Different foods spoil at different rates; a single “spoilage rate” is an approximation.
- Weather, holidays, and crises can change visitor patterns quickly; you may need to revisit your plan often.
- Real fridges have temperature gradients and hot spots that this simple model does not capture.
Because of these limits, treat the outputs as planning estimates to support discussions with your team, not as strict rules.
Practical tips and FAQs
How often should we check the fridge?
Many groups aim for at least a quick daily check, even if major restocking only happens a few times per week. The planner can show whether demand suggests you may need more frequent visits.
How do we estimate spoilage rate?
Observe the fridge over a week or two. Note roughly what fraction of food needs to be thrown away or composted each day. Start with a conservative estimate, then adjust as you gather more data.
What about heat waves or power outages?
During hot weather or when outages are common, increase the spoilage rate and downtime inputs to reflect higher risk. The tool will typically point you toward smaller, more frequent restocks or lower capacity targets.
Can we use this for multiple fridges?
Yes. Run the planner separately for each location. Visitor patterns, donation partners, and storage capacity often differ, so each fridge deserves its own plan.
How should we define a “serving”?
For planning purposes, treat a serving as roughly one person’s meal. When in doubt, slightly underestimate serving size so you do not unintentionally promise more food than you can reliably provide.
Why Community Fridge Logistics Deserve Their Own Calculator
Volunteer-run community fridges are one of the most nimble and joyful responses to neighborhood food insecurity. They redirect surplus groceries and prepared meals into an accessible, mutual aid resource that is open 24/7 and built on trust. Yet behind every well-stocked fridge sits a complex choreography of donation pick-ups, food safety considerations, volunteer labor, storage constraints, and community demand patterns. Excel sheets rarely capture the messy realities of unplanned spikes in visitors, refrigeration outages, or the fact that produce spoils faster than shelf-stable goods. This calculator is built to honor that complexity without overwhelming stewards. It provides a guided way to translate the intuition of fridge coordinators into repeatable numbers so they can make data-informed decisions about restocking frequency, volunteer scheduling, and when to campaign for more cold storage.
The form above prompts for inputs that fridge teams usually track in notebooks or messaging threads: the number of people who visit each day, how many servings they take, the average volume of donations, and how often restock visits happen. It also asks about cold storage capacity, expected spoilage rates, refrigeration downtime, and the time it takes volunteers to handle each restock. When you submit the form, the JavaScript crunches those figures to estimate daily and weekly demand, compare it to incoming supply, and highlight whether you are on track to have a surplus, a shortage, or a delicate balance. It goes a step further by modeling spoilage as an exponential decay, suggesting an optimal restock interval, and translating volunteer minutes into hours so you can check for burnout. The result panel surfaces all of that in plain language, flagging any area where the plan needs reinforcement.
How the Spoilage Model Works
Food waste dynamics differ between a fridge stuffed with prepared meals and one stocked with eggs, produce, and pantry items. To stay transparent, the calculator uses a simplified daily spoilage rate that decays the remaining servings during each day the fridge waits for the next delivery. If donations are larger than daily demand, the remainder gets multiplied by , where is the spoilage rate expressed as a decimal. The calculation for leftovers after one day can be written as:
, followed by , where is the donation volume and is daily usage. The JavaScript computes an approximate steady-state restock interval by finding the number of days after which the fridge would either run out or exceed capacity once spoilage is applied. While the math is simplified, it reflects the reality that leafy greens degrade fast and should not sit in the fridge for long stretches between deliveries.
Refrigeration downtime is another key risk. Even a few hours offline during a summer afternoon can spoil large portions of donations. The calculator treats downtime as a multiplier on the spoilage rate: for each hour of outage, it bumps the effective daily loss upward. Volunteers can use this insight to prioritize fundraising for repairs or to move especially sensitive items into coolers when they know an outage is coming. The tool also compares cold storage capacity to the size of each donation. If a single delivery exceeds available space, the result section encourages staggering drop-offs or quickly redistributing the surplus to nearby partners.
Worked Example: Fridge on a Busy Corner
Suppose you coordinate a fridge that sees 95 visitors each day, each taking an average of 1.5 servings. That amounts to 142.5 servings of daily demand. Mutual aid partners deliver about 220 servings per restock, five times per week. The fridge and adjacent freezer can hold roughly 360 servings at once. You estimate a 6 percent daily spoilage rate considering a mix of ready-to-eat dishes and produce, plus four hours of refrigeration downtime each week because the breaker trips. Volunteers spend around 40 minutes on each restock cycle, including pickup, cleaning, and stocking.
Plug those numbers into the calculator. Weekly demand becomes about 997 servings (95 visitors × 1.5 servings × 7 days), while weekly supply totals 1,100 servings (220 per delivery × 5 deliveries). The headline: there is a weekly surplus of 103 servings, suggesting room to absorb demand spikes or reduce one delivery. The algorithm estimates an optimal restock interval of 1.7 days before spoilage and storage limits create problems. Since the current schedule already averages 1.4 days between visits (seven days divided by five deliveries), the fridge is well-tuned. Volunteer workload comes to 3.3 hours per week (five deliveries × 40 minutes). The result also warns that if downtime doubles, the effective spoilage rate could push the fridge into a shortage, so scheduling an electrician visit is wise.
Scenario Comparison Table
Use the table below to compare different restocking strategies you might explore in meetings. The numbers assume the same demand profile as the example, but vary supply, spoilage, and staffing.
| Scenario | Deliveries per Week | Donation Size | Estimated Surplus/Shortage | Volunteer Hours | Risk Flag |
|---|---|---|---|---|---|
| Baseline | 5 | 220 servings | +103 servings | 3.3 hours | Watch downtime |
| Reduce Deliveries | 4 | 220 servings | -117 servings | 2.7 hours | Shortage likely |
| Increase Donation Size | 5 | 260 servings | +303 servings | 3.3 hours | Space constraints |
| Add Volunteers | 6 | 220 servings | +323 servings | 4.0 hours | Spoilage risk |
The baseline case balances supply and demand. Cutting one delivery leaves a notable shortage, hinting that any reduction must be paired with a plan to increase donation volume or reduce demand. Larger donations create more surplus but risk exceeding cold storage, so the team would need to coordinate rapid redistribution. Adding an extra delivery boosts surplus and resilience to demand spikes but also raises volunteer workload and spoilage risk. The table can anchor conversations about whether to recruit more volunteers or invest in a second fridge.
Volunteer Sustainability Table
Steward teams can use the next table to assess how changes in volunteer availability affect operations.
| Available Volunteers | Shifts per Person | Total Shifts Covered | Hours per Person | Feasibility |
|---|---|---|---|---|
| 6 | 1 | 6 | 0.55 | Manageable |
| 4 | 1 | 4 | 0.83 | Stretch |
| 3 | 2 | 6 | 1.10 | Burnout watch |
| 2 | 3 | 6 | 1.65 | Unsustainable |
By mapping total shifts against hours per person, you can advocate for volunteer recruitment drives before burnout hits. Consider cross-posting opportunities with groups already coordinating rides for the Community EV Carshare Utilization Reserve Calculator or with mutual aid crews tracking budgets using the Mutual Aid Fund Runway Calculator. Collaboration across these projects strengthens the neighborhood safety net.
Limitations and Assumptions
This calculator intentionally favors simplicity so it can run in any browser with no external dependencies. It assumes demand and donation volumes are relatively consistent week to week, even though holidays, weather, and headline news can cause dramatic swings. Spoilage is modeled as a single daily rate, which might not capture differences between leafy greens, dairy, and frozen items. Refrigeration downtime is treated as evenly distributed, whereas in reality outages may cluster. The tool also assumes that volunteer minutes per restock are constant; in practice, larger donations or deep cleaning days extend the time needed. Treat the outputs as directional guidance. Always pair them with on-the-ground observations and the lived experience of fridge users. When in doubt, err on the side of more frequent restocks and increased communication with partner organizations.
Future enhancements could include modeling separate cold and ambient storage zones, tracking specific food categories, or integrating SMS alerts when restock intervals drift. For now, the goal is to equip stewards with a transparent, shareable reference that can slide into planning decks, grant applications, or volunteer onboarding packets. Print the tables, annotate them with community insights, and update the inputs as your fridge network grows.