Community Fridge Restocking and Spoilage Planner

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.