Direct answer: start with creator-selected production minutes for the planning window, subtract protected time and already committed work, apply a creator-chosen uncertainty buffer, then divide the remaining minutes by the estimated end-to-end effort of one request type. Round down and treat the result as a planning ceiling, not a target.
This calculator estimates available custom-request production slots from creator-entered time, buffers and current workload. It does not price requests, evaluate a request concept, manage a queue, write a production brief or prescribe an output benchmark.
The calculation is intentionally conservative because a slot is a commitment of production capacity, not empty calendar space. Every input must refer to the same planning window and one sufficiently scoped request type.
Write the slot formula before choosing inputs
Use: Usable request minutes = creator-selected production minutes minus protected work minus remaining accepted-request work minus uncertainty buffer. Then use: Supported slots = floor of usable request minutes divided by end-to-end minutes for one request.
If usable minutes are zero or negative, the output is No supported slot. Do not change a negative result to zero and continue dividing; preserve the shortage because it shows that existing commitments already consume the selected window.
Round down because a fraction of a slot is not a deliverable request. Retain the unused remainder as slack. It can absorb ordinary variance or carry into a later creator decision, but it does not automatically authorise a smaller unscoped request.
Define one planning window and its available minutes
Choose the start, end and timezone. Enter only minutes the creator has approved for production during that window. Do not convert every unscheduled hour into capacity; rest, administration, existing subscriber experiences and personal commitments may already control that time.
Record the source beside the number, such as the creator's current weekly plan or confirmed shoot blocks. A copied standard workweek has no authority here. If availability is still changing, run low and high scenarios rather than hiding uncertainty inside one precise value.
Keep this request window consistent with the due horizon under consideration. A monthly pool cannot be divided by a weekly request effort and called weekly capacity without a clear allocation rule.
Subtract protected creator work first
Protected work includes feed promises, approved public promotion, recovery time and other production the creator has chosen to preserve. Capture minutes by category so a reviewer can see what the calculator is protecting.
Do not treat protected time as inefficient overhead. Removing it may create more mathematical slots while causing the creator to miss the experiences those subscribers already expect. Capacity is useful only when the whole workload remains viable.
Use the content production capacity calculator when the creator needs to rebuild the wider production allocation. Import its approved protected-minute result rather than duplicating the entire model here.
Subtract remaining effort for accepted requests
List every accepted request that still needs production work in the selected window. Estimate only the remaining stages, not the original total. A request already captured but awaiting edit should carry edit, review and delivery minutes rather than another full shoot estimate.
Keep each accepted Request ID beside its remaining minutes. This prevents the total from drifting when a request moves state. Update the calculator only from a dated queue snapshot, and never remove work because its due date feels flexible.
If the existing workload cannot be reconstructed, label capacity Needs better evidence. Opening new slots from an incomplete accepted-work total turns missing records into apparent availability.
Choose an uncertainty buffer from observed variance
The creator sets the buffer in minutes. Useful evidence includes recent setup overruns, edit revisions, access constraints, technical failures or health variability. Document the reason; a percentage copied from another business would look objective while describing the wrong production conditions.
Run the calculation with and without the buffer so its effect remains visible. If all supported slots disappear only under the buffered scenario, the creator can decide whether to pause, simplify the request type or collect better effort evidence.
Do not consume the buffer in advance by relabelling it spare capacity. It exists for uncertainty. If the window closes without using it, record that outcome for calibration rather than retroactively claiming an extra slot was available.
Estimate one request from confirmed scope
Break end-to-end effort into clarification, preparation, capture, editing, quality review, delivery and expected revision handling. Use the same stage definitions when comparing later actuals. Finished media duration alone is not an effort estimate.
Use the custom content scope confirmation form before calculating when the request type lacks a stable inclusion, exclusion or revision boundary. The calculator cannot repair ambiguous scope.
If request variants have materially different effort, calculate them separately. Averaging a simple photo set with a location-dependent edited video can produce a slot number that fits neither type.
Use the custom-request capacity calculator
Practical artifact: copy these input rows and retain the evidence source for every minute value. The arithmetic should be reproducible without relying on the person who entered it.
| Input | Creator-entered value | Evidence source | Calculation role | Review note |
|---|---|---|---|---|
| Available minutes | Minutes in this window | Creator schedule | Starting capacity | Do not use a generic workweek |
| Protected work | Feed, promotion and recovery minutes | Current commitments | Subtract | Keep promised work visible |
| Existing requests | Remaining minutes | Accepted records | Subtract | Use remaining effort, not original quote |
| Uncertainty buffer | Creator-selected minutes | Recent variance or constraint | Subtract | Document why it was chosen |
| One request effort | End-to-end minutes | Recent comparable work or stage estimate | Divide usable minutes | Round the result down |
Work a fictional slot calculation
A creator selects 600 production minutes for a week, protects 180 for promised feed work, records 120 minutes of remaining accepted work and sets a 60-minute uncertainty buffer. Usable request minutes equal 600 minus 180 minus 120 minus 60, which is 240.
If one clearly scoped request has an estimated end-to-end effort of 95 minutes, floor of 240 divided by 95 returns two supported slots with 50 minutes left. These values demonstrate the formula; they are not recommended hours, buffers or request sizes.
If the same request is re-estimated at 130 minutes after a location change, the supported result becomes one slot with 110 minutes left. The calculator changes because the production definition changed, not because demand or price changed.
Use scenarios without averaging away risk
Create a Base case from the best current evidence, a Constrained case for a known risk and an Expanded case only when additional time or simpler scope is genuinely approved. Keep all inputs visible across columns.
Do not average the three slot results. Choose the scenario that matches the operating conditions and record why. An average can return two slots when both plausible constrained conditions support only one.
Set a reopening trigger such as a new accepted request, changed creator availability, confirmed dependency or actual effort outside the estimate. Slot capacity expires when an input changes; it is not a standing quota.
Convert the result into an acceptance ceiling
The output should state planning window, request type, supported slots, evidence grade, unused minutes and approval date. A creator may open fewer slots or none. The calculation supplies an upper bound under stated assumptions, not an instruction to fill capacity.
Do not add a new request directly from this sheet. Acceptance still needs suitability, scope confirmation and creator approval. Once accepted, its remaining effort moves into the committed-work input for the next calculation.
After production, use the custom content delivery checklist for the finished asset. Delivery quality is outside the slot equation but actual stage time should return to the evidence history.
Calibrate estimates from completed requests
Compare estimated and actual minutes by stage, not just total. A stable total can hide repeated setup underruns and editing overruns that matter for different request types. Keep concept and dependency notes with the observation.
Use several comparable completed requests before replacing a creator estimate with an observed planning value. Preserve the distribution and exceptions rather than publishing an average as a benchmark.
When variance is consistently wide, increase the uncertainty allowance or narrow the request family. More decimal precision will not repair a category that combines unlike work.
Capacity-planning sources
GOV.UK Deciding on priorities, published November 16, 2017 and updated December 6, 2018, supports choosing work with limited time, materials and skills.
The official Scrum Guide, released in November 2020, supports realistic planning from past performance and upcoming capacity while recognising that more is learned during work. The slot formula is a SirenCY editorial tool, not Scrum guidance.
Limitations
Limitations: effort estimates are sensitive to concept, health, setup, revisions, technical failures and delivery conditions. A floor result can become stale as soon as workload changes. Capacity does not mean a request is suitable, approved, profitable or likely to sell.
The calculator does not determine price, due date, queue order or earnings. It cannot account for an unrecorded commitment, and its numerical output should not be presented as an industry production standard.
Creator willingness overrides available minutes. A positive result means the chosen assumptions leave mathematical room; the creator still decides whether to accept any work in that window.