Calculator Directory

Hobby Calculators

  • Boating
    High Performance Bass Boat Speed Calculator

    Enter your engine RPM, Prop Pitch in inches, and Gear Ratio and find out how fast your bass boat really goes!

  • Aquarium
    You can use these calculators to calculate volume, water chemistry, glass, design, electrics, and more..
  • Chess - Darts - Karts - Boats
    You can use these calculators to calculate chess rating, darts score, kart ratio, and bass boat speed.
  • Horses
    You can use these calculators to calculate feeding, foaling, weight, cost, and more..
  • Music
    You can use these calculators to calculate strings, chords, fretboard, neck angle, and more..
  • Rock climbing - Skydiving
    You can use these calculators to calculate canopy size, wing load, shock force, and free fall simulation.
  • Scuba Diving
    You can use these calculators to calculate weight-belt, gas consumption, MOD, SAC, and more..
  • Shooting
    You can use these calculators to calculate paintball trajectory, ballistic coefficient, distance, power, stability, and more..
  • Soap making
    You can use these calculators to calculate water, Sodium Hydroxide, fragrance, lye, cost, recipe, and more..


  • iPhone and iPod calculators
  • Aquarium
    Calculate fish tank volume, heating, and lighting requirements.
  • Darts
    Do you struggle to add up the darts to know what has just been scored? How many times have you stood there unable to do simple maths under pressure? If the answers to these questions are Yes and Lots then this App is for you. Just input what scores have been made and this App will tell you how much was scored.
  • Soap making
    Choose from the list of oils then enter the weight ( oz / g ), you can calculate the amount of sodium hydroxide and water.


  • iPad calculators
  • Soap making
    Choose from the list of oils then enter the weight ( oz / g ), you can calculate the amount of sodium hydroxide and water.