Bicycle Tools & Calculators

Compare bicycle geometry across hundreds of bikes. Stack, reach, trail — all in interactive charts.

Compare effects of fit & geo changes on the aerodynamics.

Visual geometry comparison tool. Overlay bike silhouettes to see how frames differ in size and shape.

Comprehensive geometry database with visual comparisons and detailed specs for road, gravel, and MTB bikes.

Bicycle design software for drawing your own frame down to tube angles and dimensions. Free version plus a large archive of community designs to build on.

Free to use online bike-fitting tool; make videos from the side/from front and quickly analyze position angles. Cool is, you can also adjust the points to see if adjustments would help.

Calculate your ideal bike frame size based on body measurements. Covers road, gravel, and mountain bikes.

Find the optimal crank arm length for your body proportions and riding style.

Bike-fit calculator suite built around handlebar X/Y: compare positions across bikes, work back from a target position to frame stack and reach, and find the stem, spacer and seatpost setup that hits it.

Online bike fit and sizing from a phone video: AI measures your joint angles on the bike and gives recommended ranges and adjustments. Paid subscription.

SRAM's official tire pressure calculator. Enter rider weight, tire size, and conditions for optimal pressure.

Pressure calculator from the tire experts at Rene Herse. Accounts for rider weight, tire width, and terrain.

Why does my 32mm bicycle tire inflate to 34.2mm? It's because of the rim. Therefore, meet rubbersideup.cc. A community measured bicycle tire width database which turns nominal width into WAM (Width As Measured).

Data-driven pressure calculator by SILCA. Uses extensive testing data for road, gravel, and CX tires.

Modern spoke length calculator. Enter hub and rim measurements to get exact spoke lengths for your wheel build.

Spoke calculator with a large database of pre-measured hubs and rims. Quick and accurate spoke length results.

Official spoke calculator from Sapim, one of the leading spoke manufacturers. Includes their full spoke range.

Free structured workout creator and trainer app. Build custom workouts and sync to smart trainers.

Advanced workout planning, fitness tracking, and ride analysis. Sync with Wahoo, Garmin, or upload manually.

Analyze wind impact on your cycling routes. See real-time headwind/tailwind predictions for planned rides.

Detailed weather forecasts along your cycling route. Hour-by-hour conditions for every point on your ride. Paid service.

Powerful OSM-based bike routing planner with customizable profiles, elevation analysis, and GPX export.

Explore every road and trail in your area. Track which streets you've ridden and discover new ones to complete the map.

Tile-hunting game for cyclists and runners. Collect map squares by riding through them. Compete on leaderboards.

Strava heatmap and tile explorer. Visualize your activity coverage, find cluster tiles, and track exploration progress.

Free, open-source GPX editor in the browser. Plan routes on OpenStreetMap, merge, crop and split tracks, fix elevation and inspect the profile.

Deep analysis of your Strava data: segment and activity stats, explorer tiles and Max Square. Its race hub is used by WorldTour teams and organisers.

Independent tire rolling resistance tests. Compare road, gravel, and MTB tires with standardized lab measurements.

Compare power meter and smart trainer data across devices. Useful for checking accuracy and consistency.

Independent bicycle helmet safety ratings from Virginia Tech. Lab-tested impact protection scores for hundreds of helmets.

Database of over 1,100 Chinese carbon wheelsets from around 40 brands, every spec with a source. Its highlight: all rim profiles overlaid to scale, so you can see which rim is rounder and which is narrower.

Road and gravel wheelset database. Filter and sort by rim depth, inner and outer width, weight, price, spoke count and freehub, and compare wheelsets side by side.

Try wheelsets on well-known road bikes and see how they look before buying. Also has a wheelset finder, focused on the established brands.

German bike light test site since 2012. Dynamo and battery headlights and rear lights, each measured for lumens and lux, with photos of the actual beam pattern on the road.

DC Rainmaker's tool for comparing several recordings of the same ride. Overlay power, cadence, heart rate and GPS from different devices and see which one is off and by how much.

The reference for chain lube testing: 5,000 km wear tests without cleaning, plus drivetrain efficiency in watts. Also tests chains for strength and wear.

Visual gear ratio calculator. Compare chainring/cassette combos, see speed at cadence, and analyze gear range.

Stunning interactive explainer of bicycle physics — steering, stability, gears, and more. A visual masterpiece.

The classic physics model since 1997: speed from power or power from speed, accounting for weight, grade, wind, riding position and tires.