UD5 Toolkit
Kayak Paddle Length Calculator – Your Height & Boat Width
Determine the correct paddle length for kayaking. Uses your height and kayak width to suggest the ideal shaft length for comfort and efficiency on the water.
Sports & Exercise Tools
48+ toolsMountain Bike Gear Ratio Calculator – Chainring & Sprocket
Compare mountain bike gear ratios and gear inches. Input your chainring and cassette teeth to find the perfect gearing for climbing or speed.
Snowshoe Size Guide – Weight & Terrain Recommendation
Select the right snowshoe size by entering your total weight (including gear) and the typical snow conditions. Ensures proper floatation on your winter hikes.
Ski Pole Length Calculator – Alpine, Nordic & Touring
Find your optimal ski pole length based on your height and skiing discipline (downhill, skate skiing, classic). Avoid buying poles that are too long or short.
Hike Difficulty Rating Calculator – Distance & Elevation Gain
Rate a hike's difficulty based on distance and total elevation gain using common formulas (Naismith's rule, Shenandoah). Plan your outdoor trips with confidence.
Golf Handicap Index Calculator – World Handicap System
Estimate your golf handicap index using the World Handicap System formula. Enter your recent scores, course rating, and slope rating to see your unofficial handicap.
Bowling Score Tracker – Keep Score Online Frame by Frame
Track your bowling score frame by frame. Automatically calculates strikes, spares, and open frames with a simple tap interface, so you can focus on your game.
Flip Turn Trainer – Audio Beep for Approaching the Wall
Set a repeating beep to practice your flip turns. The beep sounds when you should start your turn based on your swim speed.
Martial Arts Belt Progression Tracker – Stripes & Hours
Log training hours and stripe tests. See a visual timeline to your next belt and estimate how long until black belt based on your pace.
Dominant Eye Finder – Miles & Porta Tests
Perform the simple triangle‑hand test or Porta test with interactive on‑screen instructions to determine which eye is dominant.
Barbell Plate Load Calculator – Online Weight Room Math
Enter target total weight and bar weight to see which plates to put on each side. No more counting errors.
Golf Handicap Differential Calculator – Online Score to Index
Enter adjusted gross score, course rating, and slope to calculate the round's handicap differential. Track your index.
Archery Sight Tape Generator – Custom Yardage Marks
Create a printable sight tape for your bow sight based on arrow speed. Enter FPS or IBO rating and get precise yardage marks for hunting and 3D archery.
Bow Sight Pin Gap Estimator – Online Multi‑Pin Setup Tool
Enter your first pin distance and arrow speed to estimate gaps for 30, 40, 50, 60 yard pins. Start practice.
Stand Up Paddle Board Volume Calculator – Weight & Skill
Find the right paddle board volume for your body weight and skill level. Convert liters to recommended board dimensions for optimal stability and performance.
Ski Binding DIN Calculator – Online Weight, Height, BSL, Skier Type
Enter your weight, height, boot sole length, and skier type to see the recommended DIN release setting.
Disc Golf Bag Builder – Online Select Discs & Visualize Flights
Add discs by speed, glide, turn, fade to build a balanced bag. See slot gaps. Print your in‑the‑bag list.
Wing Loading Calculator – Online Skydiving & Paragliding Safety
Enter your exit weight and canopy size to calculate wing loading. Helps determine if you're within the safe recommended range.
Surfboard Volume Estimator – Online Dimensions to Liters
Enter length, width, thickness to approximate surfboard volume. Compare to your ideal volume based on weight.
Arrow Spine Selector – Online Draw Weight & Point Weight Tool
Enter your bow's draw weight, arrow length, and point weight to find the correct arrow spine. Essential for tuning.
Overgrip Length Calculator – Online Racket Handle Wrapping
Measure your handle circumference and preferred overlap to see how long your overgrip tape needs to be.
SCUBA Gas Consumption Planner – Online SAC Rate & Tank Volume
Enter your Surface Air Consumption rate and planned depth to estimate how long a cylinder will last. Dive safely.
Bowling Score Calculator - Online Frame by Frame Tracker
Enter pins per roll and calculate total bowling score including strikes and spares. Supports 10 frames. Learn scoring rules visually.
Golf Handicap Calculator - Online Quick Index Estimator
Enter recent scores, course rating, and slope to estimate a golf handicap index. Simple formula for unofficial tracking. Local only.
8‑Ball & 9‑Ball Rack Arranger – Correct Ball Order
Shows the correct placement of balls in the rack for 8‑ball, 9‑ball, and straight pool. Never be unsure of the rules again.
Wetsuit Thickness Selector – Online Water Temp & Activity
Enter water temperature and activity to get recommended wetsuit thickness (2/3mm to 6/5mm). Stay comfortable.
Candlepin Bowling Score Calculator – Online Small Ball Scoring
Keep score for candlepin bowling with its unique rules. No strike carries automatic strikes. For New England enthusiasts.
Golf Club Distance Logger – Online Track Average Carry per Club
Record shot distances for each club and see averages. Identify gaps in your bag. Local storage.
Discus Optimal Release Angle Calculator – Online Physics Estimator
Enter release height and speed to compute the optimal launch angle for maximum distance. Simple projectile model.
Kayak Weight Capacity Calculator – Online Paddler + Gear Limit
Enter kayak's maximum capacity and your weight to see remaining capacity for gear. Safety on the water.
Skateboard Wheel Durometer Selector – Online Surface Match
Choose your riding surface (street, park, vert, rough) and get a recommended wheel hardness (78A‑101A) and size.
Yoga Mat Thickness Selector – Online Joint & Surface Needs
Answer questions about sensitivity, surface, and travel to get the ideal mat thickness.
Digital Swim Pace Clock – Online Interval Training Timer
Large screen pace clock with programmable send‑offs. Perfect for masters swimming workouts. Confirms your rest time.
Snowboard Stance Width Finder – Online Height & Riding Style
Enter your height and riding style to get a recommended stance width and binding angles. Centered and balanced.
Ski Wax Temperature Guide – Online Nordic & Alpine Glide Wax
Enter air and snow temperature plus humidity to get the right glide wax color (Swix/Toko). Perfect kick and glide.
Climbing Grade Converter – Online V‑Scale to Font & YDS
Convert climbing difficulty between V‑scale, Fontainebleau, and Yosemite Decimal System. Quick reference for gym climbers.
Erg Stroke Rate & Split Predictor – Online Concept2 Pace Chart
Enter distance and time to get your 500m split. Also predicts how a change in stroke rate affects power output.
Skateboard Deck Size Selector – Online Shoe Size & Style
Select shoe size and riding style to get recommended deck width. Visual comparison.
Bike Fit Calculator - Online Saddle & Frame Size
Enter your body measurements and get approximate bike frame size, saddle height, and reach. For cyclists. Local.
Disc Golf Putting Probability Calculator - Online C1X/C2 Stats
Estimate make probability of a putt based on distance and skill rating. For disc golf enthusiasts. Fun statistical tool, no data upload.
Running Splits Calculator - Online Race Pace Predictor
Enter a recent race time and predict times for other distances. Also get lap splits for different intervals.
Ultra Marathon Pace Band Generator - Online Print Splits
Generate a printable pace band for ultra distances with mile/km splits and cumulative time. Adjust for terrain.
Swim Pace Calculator - Online 100m / 100yd Time Predictor
Calculate swim pace per 100m or 100yd based on total time and distance. Predict race times. For pool and open water swimmers.
Running Shoe Size Converter - Online US UK EU CM Chart
Convert running shoe sizes between US (men/women), UK, EU, and centimeters. Also includes brand-specific fit notes (general guide).
Bike Saddle Height Calculator – Online Inseam Method
Enter your inseam length to get suggested saddle height using the LeMond or 109% method.
Tennis String Tension Guide – Online Racquet, String & Play Style
Select your racquet head size, string type, and play style to get a recommended tension range. Find your sweet spot.
Bike Gear Inch & Ratio Calculator - Online Cycling Tool
Calculate gear inches, meters of development, and speed ratio for any chainring/cog combination. For cyclists.
Tennis Scoring Simulator - Online Point Tracker
Keep track of a tennis match: points, games, sets, and deuce. Supports tiebreak. Great for friendly matches. Local.