I like this one. But only gives readings for Winchestor ammo, which is usually what I use anyway.

Winchestor Ballistics Calculator

Computer generated charts are just rough estimates with variables - air density, wind speed, wind direction, and distance, being the major ones- which need confirmation on a range - assuming you have an accurate known bullet velocity, not the marketing hype off the back of the box.

Best practice is to hang targets and document what your rifle, scope, and ammo combo really does at fixed known distances.

Recheck with different temperatures consistently using the same ammo, as velocities drop as temperatures drop, sometimes substantially depending on the powder used. The change in velocity can and will alter elevation and windage corrections, more so the longer the distance.

Keep records, and then prepare a summary table and tape it to your rifle on the side for reference.

Importantly, limit shots to those that you KNOW you can make i.e. know the required data and have practiced.