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Calcimator

QSL Card Distance Calculator

Calculate great circle distance and bearing between two Maidenhead grid squares for QSL cards and contest logging.

Inputs

Results

Distance (Short Path)

10,777.9 km

≈ 255 marathons

Bearing (Short Path)

86.2°

Distance (Short Path)6,697.1 mi
Long Path Distance29,252.3 km
Long Path Bearing266.2°
Est. HF Hops4
Your Latitude-45.479°
Your Longitude-80.958°
DX Latitude7.604°
DX Longitude11.208°
Propagation Time Ms35.95
How to Use This Calculator
  1. Enter your grid square using the field number, square digit, sub-square letter, and sub-digit.
  2. Enter the DX station's grid square in the same format.
  3. Review short-path distance (km and miles) and bearing toward the DX station.
  4. Use long-path distance and bearing to point your beam in the opposite direction if propagation favors it.

How the result changes with DX Grid: Field (1-18)

DX Grid: Field (1-18)Distance (Short Path)Bearing (Short Path)
2.73,876.4 km216°
6.953,768.6 km58.8°
1215,386.4 km98.6°
1616,934.5 km334.1°

What each input means

Your Grid: Field (1-18 = A-R)
First character of your grid (A=1, B=2...R=18). E.g., EN34 → E=5
Your Grid: Square (0-9)
Second character of your grid (digit 0-9)
Your Grid: Subsquare (1-24 = a-x)
Third character of your grid (a=1, b=2...x=24)
Your Grid: Sub-digit (0-9)
Fourth character of your grid (digit 0-9)
DX Grid: Field (1-18)
First character of remote station grid
DX Grid: Square (0-9)
Second character of remote station grid
DX Grid: Subsquare (1-24)
Third character of remote station grid
DX Grid: Sub-digit (0-9)
Fourth character of remote station grid

How this is calculated

Formula

Haversine: d = R × arccos(sin φ₁·sin φ₂ + cos φ₁·cos φ₂·cos Δλ)

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Your Grid: Field (1-18 = A-R) = 5, Your Grid: Square (0-9) = 9, Your Grid: Subsquare (1-24 = a-x) = 13, Your Grid: Sub-digit (0-9) = 4 = 8 input(s) provided
  2. Calculate Distance
    Distance
    10777.9 = 10777.9
  3. Calculate Bearing
    Bearing
    86.2 = 86.2
  4. Calculate Distance
    Distance
    6697.1 = 6697.1
  5. Calculate Long Path Distance
    Long Path Distance
    29252.3 = 29252.3

Engine last updated . Checked against 1 independently-derived test — how we verify calculators.

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