Don’t worry if you weren’t at the top of your eight-grade math class. Calculating maximum point-blank range (MPBR) can be as easy as punching a few numbers into a ballistics calculator and spending a little time at the range. But if you want a quick ballistic reference tool for while you’re in the field, you don’t need to look any further than your smart phone. There are a host of apps available that will give you the dope on every conceivable caliber and bullet. Here are three of my iPhone favorites.

Winchester Ballistics Calculator: A version of the ballistic calculator found on Winchester Ammo’s website is also available as an iPhone app, which allows you to compare up to three bullet types with easy-to-read high-tech graphs and charts, and view product information and product images. Select your caliber and bullet, punch in the range and weather conditions and pull the (virtual) trigger. The app will give you instant feedback on bullet drop and drift.

Ballistic: This baby was designed for serious shooters who want a ballistics calculator with all the bells and whistles. It calculates trajectory, windage, velocity and energy, and it can compensate for atmospheric conditions such as temperature, barometric pressure, humidity and altitude. With a vast library of more than 4,800 projectiles and factory loads, Mil-Dot and MOA rangefinder with heads-up display capabilities, GPS and atmosphere awareness, full-size charts, and much more, Ballistic is a complete precision marksman tool for hunting and shooting. Available in Standard and Advanced editions.

Mil-Dot Ballistics: Perfect for hunters and shooters, Mil-Dot Ballistics is a full-featured app that provides instant range estimation and ballistics calculations that will get you on target fast. It has all the features you’d expect from a portable ballistics calculator, and it will give you instant feedback on bullet drop, velocity and energy for your favorite whitetail cartridges.