This guide credits to Treillerti ( Original Page )

Pet Stamina & Growth Rate Per Level Every wonder how high number's get for pet's. .  Even though you can easily add them level by level, here's a more easy chart. (Stamina/Growth) - Rations needed)  ~ Time Per 60secs (Without 3 skills) - Time per 30 secs (With 3 skills) Lv1:    120/240  - 5  ~ 4 hours - 2 hours Lv2:     140/480 - 10 ~ 8 hours - 4 hours Lv3:     160/720 - 15  ~ -12 hours - 6 hours Lv4:     180/960 - 20  ~ 16 hours - 8 hours Lv5:   200/1200 - 24  ~ 20 hours - 10 hours Lv6:   220/1440 - 29  ~ 1 Day (24 hours) - 12 hours Lv7:   240/1680 - 34  ~ 1 Day 4 hours - 14 hours Lv8:   260/1920 - 39  ~ 1 Day 8 hours - 16 hours Lv9:   280/2160 - 44  ~ 1 Day 12 hours - 18 hours Lv10: 300/2400 - 48  ~ 1 Day 16 hours - 20 hours Lv11: 320/2640 - 53  ~ 1 Day 20 hours - 22 hours Lv12: 340/2880 - 58  ~ 2 Days (48 hours) - 1 Day (24 hours) Lv13: 360/3120 - 63  ~ 2 Days 4 hours - 1 Day 2 hours Lv14: 380/3360 - 68  ~ 2 Days 8 hours - 1 Day 4 hours Lv15: 400/3600 - 72  ~ 2 Days 12 hours - 1 Day 6 hours Lv16: 420/3840 - 77  ~ 2 Days 16 hours - 1 Day 8 hours Lv17: 440/4080 - 82  ~ 2 Days 20 hours - 1 Day 10 hours Lv18: 460/4320 - 87  ~ 3 Days (72 hours) - 1 Day 12 hours Lv19: 480/4560 - 92  ~ 3 Days 4 hours - 1 Day 14 hours Lv20: 500/4800 - 96  ~ 3 Days 8 hours - 1 Day 16 hours Lv21: 520/5040 - 101 ~ 3 Days 12 hours - 1 Day 18 hours Lv22: 540/5280 - 106  ~ 3 Days 16 hours - 1 Day 20 hours Lv23: 560/5520 - 111  ~ 3 Days 20 hours - 1 Day 22 hours Lv24: 580/5760 - 116  ~ 4 Days (96 hours) - 2 Days (48 hours) Lv25: 600/6000 - 120  ~ 4 Days 4 hours - 2 Days 2 hours Lv26: 620/6240 - 125  ~ 4 Days 8 hours - 2 Days 4 hours Lv27: 640/6480 - 130  ~ 4 Days 12 hours - 2 Days 6 hours Lv28: 660/6720 - 135  ~ 4 Days 16 hours - 2 Days 8 hours Lv29: 680/6960 - 140  ~ 4 Days 20 hours - 2 Days 10 hours Lv30: 700/7200 - 144  ~ 5 Days (120 hours) - 2 Days 12 hours Lv31: 720/7440 - 149 Lv32: 740/7680 - 154 Lv33: 760/7920 - 159 Lv34: 780/8160 - 164 Lv35: 800/8400 - 168 Lv36: 820/8640 - 173 Lv37: 840/8880 - 178 Lv38: 860/9120 - 183 Lv39: 880/9360 - 188 Lv40: 900/9600 - 192 Lv41: 920/9640 - 197 Lv42: 940/10080 - 202 Lv43: 960/10320 - 207 Lv44: 980/10560 - 212 Lv45: 1000/10800 - 216 Lv46: 1020/11040 - 221 Lv47: 1040/11280 - 226 Lv48: 1060/11520 - 231 Lv49: 1080/11760 - 236 Lv50: 1100/12000 - 240 (Current Estimated Total Rations: 6,266 (@50)) ~ < Estimated Total Times 1860 HOURS or 77 days and 12 hours - 930 HOURS or 38 days and 18 hours > I recently heard that a GM has a  Lv100 Fairy, so in knowledge of that, I will be taking the chart up that high, little by little. . Fun. Hope this helps you figure out how much you'll be spending per fairy, and yes it DOES get very expensive after awhile. .