Input page
This page is the foundation of the app. Every calculation—trajectory, impact charts, penetration, drag, and sight tapes—depends on the measurements you enter here.
Below is a full explanation of each section and field.
🟠 1. Bow Library
Click here to access Bow Library
- Opens your saved bow setups.
- Load a stored bow profile or create a new one.
A separate written tutorial can be found for the bow library feature.
🟠 2. Arrow Builds
Select Build Number
- Chooses which arrow profile you’re editing (Build 1, Build 2, Build 3, etc.).
- Each build has its own mass, length, fletchings, drag, and speed values.
- You can compare each of the 5 builds on this page through the app for example on the dual tape page.
🟠Select Point Type (For penetration estimate based on Poncelet model)
- Options include Field Point, and Broadhead.
- When Broadhead is selected input fields appear in Broadhead section below.
- Used only for penetration modeling, not trajectory.
🟠Build Name
- Name this setup (e.g., “450gr Hunting”, “3D setup”, “Indoor Setup”).
- This name will be displayed through the app for easier reference to what the build is.
🟠 Use Marks or Pin Gaps from Sight Tapes
(Toggle Switch)
- OFF (default): The app uses speed + geometry + drag for sight tape generation.
- ON: You manually enter pin gaps or distance marks from your actual sight tape to generate a calibrated custom tape.
🟠 3. Air Density
Click here to determine density
- Opens the Air Density calculator.
- Input:
- Temperature
- Humidity
- Barometric Pressure (measured by phones on-board sensor)
- The app calculates Air Density, which improves long-range accuracy.
🟠 4. Bow Measurements
- These measurements directly affect sight tape scaling and trajectory alignment.
Distance from pin to center of peep while at full draw
- Measure from the sight pin (or center of housing if using a slider) to the middle of your peep while fully drawn.
- Units: Inches
- Critical for the geometric model of angular sight movement.
Center of arrow to center of peep while at full draw
- Vertical distance from arrow shaft centerline to the center of the peep at full draw.
- Units: Inches
- This influences your sight angle and zero reference.
🟠5. Arrow Measurements
- These fields define the projectile’s physical and aerodynamic characteristics.
Initial Velocity / Speed
- Enter your chronograph speed.
- Units: feet/sec
If unknown, shoot an arrow through a chronograph before using the method or toggle build data with marks above.
📏 Calculate Drag With Downrange Velocity (Optional)
Click here to enter Downrange velocity
- Allows you to enter:
- A distance value (eg. 60 yards)
- Measured speed in feet/sec at that distance. (Using LabRadar, Garmin chronograph, or other)
- The app uses these values to calculate real CD/drag, replacing the standard model.
- Fill out all arrow fields first, then enter downrange speeds.
⚖️ Arrow Physical Specs
Arrow Mass
- Total arrow weight in grains including insert, point, vanes, wrap, everything.
Arrow Outside Diameter (OD)
- Enter the Outside Diameter of the shaft.
Example: - Micro (4mm): 0.24-0.27 depending on arrow spine.
- Standard (5mm): 0.25 - 0.29 depending on arrow spine.
- Do not use inside diameter!
Total Arrow Length
- Full arrow length end of nock to end of point
- Units: inches
🪶 Fletching Details
Number of Fletchings
- Typically 3 or 4, but you can enter any value.
Fletching Length
- Length of each vane.
- Units: inches
Fletching Height
- Height of vane from shaft surface.
- Units: inches
Fletching Angle
- Helical or offset angle in degrees.
- Higher angle = more spin = more drag, increasing stability but reducing speed.
🟠 Broadhead Measurements
- These fields define the broadheads physical properties and are used for Poncelet penetration estimates shown on the Table tab.
Main blade length
- Enter the length of the blade (when extended for mechanicals) from the start of the blade to the end of the blade along the ferrel or length of the arrow shaft.
- Unit: Inches
Main blade cutting diameter divided by 2.
- Use the product package to take the cutting diameter and divide by 2 this will give the height of each blade including 3 blade broad heads. Diameter is listed on packaging or on manufactures website.
- Unit: Inches
Number of main blades
- For a 2 blade enter 2
- For a 3 blade broadhead enter 3
- For a 4 blade where each blade is the same size enter 4.
- For a 4 blade with two large blades and two bleeder blades enter 2
Main blade thickness
- Enter the thickness of the blade in inches (measure with calipers)
- Unit: Inches
Secondary blades
When no secondary blades entering 0 takes all secondary blade measurements out of the calculations.
Secondary blade fields are the same as Main Blades.
Blade Sharpness factor
- Click the orange value drop down default is (1 standard sharp)
- Options from list include 2.0 dull/blunt, 1.4 working edge, 1.0 standard sharp, 0.8 very sharp, 0.6 shaving sharp, 0.4 scary sharp.
Most broad heads are between a working edge and standard sharp unless sharpened with a leather strop.
Broadhead Type
- Options include blade first, trocar, chisel, and cone.
- Select the most appropriate tip design for each broadhead.