Why A1Z26?
A1Z26 is the workhorse of geocaching puzzles for good reasons:
- Mathematical flexibility — Numbers can be added, multiplied, or used in formulas
- Natural for coordinates — Results are already numbers
- Easy to disguise — Numbers blend into many contexts
- Reversible applications — Can encode text OR decode field counts
The Basics
A1Z26 uses a simple mapping:
A=1 B=2 C=3 D=4 E=5 F=6 G=7 H=8 I=9
J=10 K=11 L=12 M=13 N=14 O=15 P=16 Q=17 R=18
S=19 T=20 U=21 V=22 W=23 X=24 Y=25 Z=26
Example encoding:
CACHE → 3 1 3 8 5
Example decoding:
14 15 18 20 8 → NORTH
Common Puzzle Patterns
Pattern 1: Direct Encoding
Simply encode your message as numbers. Best for short, clear messages.
Puzzle:
7 15 / 23 5 19 20
Solution: GO WEST
Pattern 2: Word Value Formula
Use the sum of letter values in a word to generate coordinate digits.
Formula:
N 51° AB.CDE where AB = value of TREE, CDE = value of OAK
TREE = 20+18+5+5 = 48, OAK = 15+1+11 = 27 → N 51° 48.027
Pattern 3: Field Puzzle
Count objects in the field, then decode using A1Z26.
Cache description:
"Count the fence posts. What word do you see?"
Fence posts: 8, 5, 18, 5 → HERE
Pattern 4: Hidden in Plain Sight
Embed A1Z26 numbers within seemingly normal text.
Cache description:
"I walked 14 miles to find 15 geocaches in 18 days across 20 countries while wearing 8 different shoes."
Numbers: 14, 15, 18, 20, 8 → NORTH
Handling Number Separators
Since A1Z26 produces numbers, you need clear separation to avoid ambiguity:
Spaces or commas
3, 1, 3, 8, 5 or 3 1 3 8 5
Dashes or dots
3-1-3-8-5 or 3.1.3.8.5
Fixed width (zero-padded)
03 01 03 08 05
Avoid ambiguity: "1126" could be "1-1-26" (AAZ), "11-26" (KZ), "1-12-6" (ALF), etc. Always use clear separators unless ambiguity is intentional!
Difficulty Variations
Easy (D1-D1.5)
- • Clear number separation
- • Hint that it's A1Z26 ("A=1, B=2...")
- • Numbers in sequence without math needed
Medium (D2-D2.5)
- • Don't name the cipher, but hint at alphabet/numbers
- • Numbers embedded in text or images
- • Simple math with word values
Hard (D3+)
- • Reverse A1Z26 (use letters to represent numbers)
- • Combine with other ciphers
- • Complex formulas using word values
- • No hints about the encoding method
Complete Example Puzzle
Cache Title: "Elementary Mathematics"
The title hints at simple number operations.
Cache description:
"The final coordinates are hidden in plain sight. Remember your ABCs—every letter has its place.
N 51° (TREE).(BARK)
W 000° (LEAF).(BRANCH)
Calculate each word's total value and you'll find your way."
Solution:
TREE = 20+18+5+5 = 48
BARK = 2+1+18+11 = 32
LEAF = 12+5+1+6 = 24
BRANCH = 2+18+1+14+3+8 = 46
Final: N 51° 48.032 W 000° 24.046
Pro Tips
- Use our Word Value tool. The Word Value calculator lets you quickly find words that sum to specific numbers.
- Check coordinate validity. Before publishing, verify that all your calculated coordinates point to accessible, safe locations.
- Provide sanity checks. Include a coordinate checker or give the solver a way to verify their intermediate answers.
- Consider leading zeros. If your formula produces "27" but you need "027", make this clear in the puzzle format.