Halloween calculators
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Plan Halloween before October 31: estimate trick-or-treat candy for your door or classroom, carve pumpkins at the right time, weigh giant pumpkins with the Great Pumpkin Commonwealth formula, size punch and dry-ice fog, and check whether inflatables plus light strands fit one household circuit. Live countdown to Halloween with sleeps and shopping weekdays.
For full Halloween parties see our event calculators — party food, drinks, pizza, and ice. DIY costume fabric yardage lives in sewing calculators. Compare yard display wattage results with our appliance energy cost tool for kWh estimates. These tools use US planning defaults where noted; candy and fog math is universal once you enter your own counts.
11 tools in this section
Days Until Halloween
Count down to the next Halloween (October 31) from today. Shows Happy Halloween on the night and rolls to next year after October 31 passes.
Trick-or-Treat Candy
Estimate Halloween candy for your front door, a classroom party, or neighborhood turnout. Switch door, classroom, or estimate modes with weather adjustments.
Pumpkin Carve Date
Find the earliest carve date so your jack-o'-lantern still looks good on display night. Enter display end date and expected shelf life in days.
Pumpkin Puree
Convert fresh pumpkin weight to cups of puree and standard pie counts. Switch US pounds or metric kilograms with automatic value remapping.
Pumpkin Weight Calculator (OTT)
Estimate giant pumpkin weight from circumference and axis measurements using the Over-The-Top (OTT) formula. US inches or metric centimeters.
Pumpkin Seed
Estimate cups of roasted pumpkin seeds from pumpkin weight, sheet pans needed, and approximate roast time for Halloween leftovers.
Halloween Punch
Estimate total punch volume from guest count, ounces per guest per hour, and party length. Results in fluid ounces, gallons, and liters.
Dry Ice
Estimate dry ice pounds for a fog duration and burn rate. Party planning heuristic only — not a safe exposure dose; see CDC carbon dioxide guidance.
Halloween Display Wattage
Total watts for inflatables and light strands versus a typical 15-amp circuit at 80% load. See if you need extra circuits for outdoor Halloween décor.
Candy Jar
Estimate how many candies fit in a jar from jar volume, packing fraction, and single-piece volume. Includes low–high band for guessing games.
Caramel Apple
Calculate total caramel grams and batch count from apple count, grams per apple, and grams per recipe batch for Halloween treats.