The Haunts page and the Reviews page rank the seven main Des Moines-area haunted houses by a single combined rating. This page explains how that number is calculated.
The sources
Ratings are gathered from four sources: Google, Facebook, Yelp, and Apple Maps. Google and Yelp rate out of 5 stars; Facebook and Apple rate as a percentage (for example, 94% or 87%).
Step 1: Put every score on a 5-star scale
Star ratings are already on a 5-star scale and are used as-is. Percentages are divided by 20, so 100% becomes 5.0, 94% becomes 4.7, and 75% becomes 3.75.
Step 2: Combine with a weighted average
Each source’s converted score is multiplied by how many ratings that source has. Those products are added together, and the total is divided by the total number of ratings across all sources. In other words, a source with many ratings counts for more than a source with few: 989 Facebook ratings pull the combined score far harder than 13 Yelp ratings.
A worked example: Slaughterhouse
Using the ratings as of October 26, 2026:
- Google: 4.6, from 728 ratings
- Facebook: 94%, which converts to 4.7, from 989 ratings
- Yelp: 4.1, from 13 ratings
- Apple: 87%, which converts to 4.35, from 15 ratings
(4.6 × 728 + 4.7 × 989 + 4.1 × 13 + 4.35 × 15) ÷ 1,745 = 4.65. The combined rating is 4.65, and the 1,745 in parentheses is the total number of ratings behind it.
A second example: a haunt with few reviews
Zombie Hollow has far fewer ratings than Slaughterhouse — 75 in total — and its scores are spread out, which makes the effect of weighting easy to see. Using the ratings as of October 26, 2026:
- Google: 4.9, from 39 ratings
- Facebook: 94%, which converts to 4.7, from 31 ratings
- Yelp: 5.0, from 1 rating
- Apple: 75%, which converts to 3.75, from 4 ratings
(4.9 × 39 + 4.7 × 31 + 5.0 × 1 + 3.75 × 4) ÷ 75 = 4.76. A plain average of the four scores would give (4.9 + 4.7 + 5.0 + 3.75) ÷ 4 = 4.59 — noticeably lower. The difference is Apple’s low 3.75 and Yelp’s perfect 5.0: each would count for a full quarter of a plain average, but under weighting they count for only 4 of 75 ratings and 1 of 75 ratings, so neither one swings the result. That is the point of weighting: a handful of ratings cannot outweigh dozens of them.
At the extreme, Future Nightmares has only 13 ratings, all from Google, so there is nothing to weight — its combined rating is simply its Google score.
Sources with no ratings are left out
If a source has no ratings for a haunt, it contributes nothing — it is not counted as zero. For example, Future Nightmares’ combined rating comes from Google alone, because it has no ratings on the other sources. The Docks’ combined rating has no Yelp component, because its Yelp listing has no reviews.
Ties
When two haunts display the same rounded score, the one with more ratings ranks higher. For example, Carlisle Haunted Woods (4.70, 99 ratings) ranks above Future Nightmares (4.70, 13 ratings).
When the rankings change
The combined ratings are recalculated whenever the underlying ratings are refreshed, so a haunt’s score — and its rank — moves as new reviews come in. The rankings show the date they were last calculated.
See the current rankings on the Haunts 2026 page and the Reviews page.