Start from the money in and out
The budget for an outing is short: the entry fees you collect, minus what the course, caterer and suppliers charge you, equals what you can spend on prizes or keep for a cause. The calculator does that in one line: entry fee x players, minus per-player costs x players, minus fixed costs.
The per-player costs are things like green fees, carts and the meal, charged per head. Fixed costs are things that do not change with the field size, such as signage, prizes you buy and equipment rentals. Put sponsorship income in by lowering the fixed cost.
The payout table
The table splits the prize pool by a common starting percentage for the number of places you choose: one place takes everything, two places split 65/35, three places 50/30/20, four places 40/30/20/10, five places 35/25/20/12/8 and six places 30/22/18/14/10/6. These are starting points to edit to taste, not a rule. Amounts are rounded to whole dollars using the largest remainder method, so the payouts always add up to the pool exactly.
How many places should you pay?
There is no single rule. Paying more places keeps more of the field interested to the end; paying fewer makes the top prizes worth chasing. If you run flights, pay each flight separately. The guide to running an outing covers this.
Skill and chance
This is a budgeting tool for the organizer. The entry fee and prizes are handled by you and the venue, not by any app, and local rules about prizes and raffles vary, so check what applies to your event.