Live planning model
Compare two genuinely different wedding designs
Model each design with its own attendance, fixed experience, guest-driven spend, travel support, and reserve. The result shows protected totals and funding gaps without pretending cost alone measures meaning or quality.
| Design component | Design A | Design B | A minus B |
|---|
Current calculation process
Formula, default substitution, intermediate quantities, and check
T_j = (fixedScope_j + guests_j x perGuest_j + travelSupport_j) x (1 + contingency_j)
Each design has an independent attendance and cost structure but shares one available-funds boundary. Incremental cost per guest-count change is defined only when the guest counts differ.
Five-step design comparison
Define the event before ranking dollars
- Describe each design in plain language: attendance, place, duration, experience, access, and priorities.
- Separate each design’s fixed commitments from costs that scale with its guest count.
- Enter travel or lodging support explicitly rather than burying destination effects in other categories.
- Choose independent contingencies based on each design’s unresolved scope and compare both against common available funds.
- Review totals, gaps, and component differences alongside non-financial priorities; preserve assumptions and the exported report.
Five scenario concepts
Why this is not a package comparison
Independent attendance
Each design can host a different guest count because attendance is part of the decision, not a normalization input.
Fixed experience scope
Venue, media, attire, entertainment, and production can change even when guest count falls.
Guest-driven spend
Per-guest cost converts each design’s attendance into food, beverage, rental, and favor scope.
Travel support
A smaller destination event can carry substantial transport or lodging support not captured by attendance alone.
Independent uncertainty
Each design receives its own contingency because unresolved vendor and travel scope can differ.
Symbols and default substitution
Protect each design separately
| Symbol | Meaning | Design A | Design B |
|---|---|---|---|
| G | Guests | 140 | 82 |
| F | Fixed scope | $16,500 | $20,500 |
| q | Per-guest spend | $165 | $205 |
| R | Travel support | $2,200 | $6,800 |
| c | Contingency | 10% | 12% |
| A | Available funds | $44,000 | |
Default substitution: A = (16,500 + 140 x 165 + 2,200) x 1.10. B = (20,500 + 82 x 205 + 6,800) x 1.12. Each gap is max(0, protected total - 44,000).
Three decision lenses
Interrogate what the difference means
Guest-count marginality
The signed cost change divided by signed attendance change is descriptive across two designs; it is not the saving from removing one guest while all other scope stays fixed.
Travel equity
Consider who bears flights, lodging, time off, mobility constraints, and childcare even when the couple’s entered support cost is low.
Preference boundary
A lower protected total does not score cultural meaning, relationships, atmosphere, accessibility, or vendor quality.
Two design cases
Different attendance and equal-attendance boundary
Large local versus smaller destination
The default run gives the destination design fewer guests but greater travel support and fixed experience scope. The ledger reveals whether attendance reduction offsets those choices.
Equal guest counts
When both designs use the same attendance, signed incremental cost per guest-count change is not defined because the denominator is zero. Totals and gaps remain valid.
Terms
Design-scenario vocabulary
- Event design
- A coherent attendance, place, experience, and support concept.
- Fixed scope
- Entered commitments that do not vary directly with guests.
- Guest-driven spend
- Attendance multiplied by a design-specific per-guest amount.
- Travel support
- Couple-funded transport, lodging, or access assistance.
- Protected total
- Base design cost plus its own contingency.
- Funding gap
- Positive excess of protected total over common funds.
Design-scenario questions
Frequently asked questions
How is this different from the wedding package comparison?
This page allows different guest counts and different event designs. The package comparison normalizes two vendor offers at one common attendance.
What belongs in fixed scope?
Enter design commitments that do not directly scale with guests, such as venue, attire, photography, entertainment, and production.
Why is travel support separate?
It makes destination or accessibility support visible rather than hiding it in fixed scope or per-guest spend.
Can the two designs use different contingencies?
Yes. Each design may have different unresolved scope, vendor certainty, or travel exposure.
Why can incremental cost per guest be negative?
It is a signed total-cost difference divided by a signed guest-count difference. Its sign follows the direction from Design B to A.
What happens when guest counts are equal?
The incremental cost per guest-count change is not defined because the denominator is zero; totals, gaps, and component differences still calculate.
Limits and evidence
Cost cannot choose the meaningful design
- The model uses one per-guest rate and one contingency per design.
- Travel support includes only costs paid by the couple, not the full burden on guests.
- Guest acceptance, vendor minimums, taxes, fees, and payment timing are not inferred.
- Incremental cost across designs is not a causal marginal-guest estimate.
Evidence record: retain design briefs, guest assumptions, vendor proposals, travel-support policy, contingency rationale, funding evidence, and exported scenario report. This is planning support, not a judgment about relationships or event value.
Sources and related tools
Connect scenarios back to budget and cash flow
- CFPB: Budgeting guidance — align planned spending with resources and goals.
- CFPB: Your Money, Your Goals toolkit — planning and tracking resources.