Aquarium Salt Calculator
Aquarium salt grams from tank volume and ppt with change recharge.
Biology and Life
Genetics, growth, and animals. Simple models with the formula shown.
Aquarium Volume Calculator
Tank gallons, liters, and water weight from inside length, width, and height.
Baby Blood Type Calculator
Possible child blood types from both parents' types.
Bacteria Growth Calculator
Final cell count from starting cells, doubling time, and hours.
Bat House Calculator
Bat boxes needed from colony size, with mounting rules.
Bird Count Tally Calculator
Turn checklists, species averages, and birds per species into survey totals.
Birdhouse Size Calculator
Entrance hole, floor size, and mounting height for common backyard birds.
Cat Age Calculator
Human years and life stage for any cat age from AAHA charts.
Cat Food Calculator
Daily calories and cups for cats from weight, life stage, and food energy.
Cat Litter Box Calculator
Turn cat count and top up rhythm into boxes and monthly top ups.
Cat Pregnancy Calculator
Due date, kittening window, and vet checks from mating date for queens.
Chicken Coop Size Calculator
Coop, run, nest boxes, and roost from flock size and breed.
Chicken Egg Production Calculator
Flock egg counts by hens and lay rate.
Chicken Feed Calculator
Daily and monthly feed with bag days and cost for any flock.
Chicken Run Size Calculator
Chicken run and coop area from flock size.
Chicken Water Calculator
Flock water gallons and drinker days from hens and heat.
Chill Hours Calculator
Suitability verdict and surplus from variety requirement and local chill hours.
Christmas Tree Water Calculator
Cut tree daily water from trunk diameter with stand sizing rules.
Compost Mix Calculator
Browns needed for a 30:1 pile from any greens weight.
Cover Crop Seed Calculator
Cover crop seed pounds, bags, and rate per acre.
Cow Gestation Calculator
Calving due date and watch window from the breeding date.
Deer Gestation Calculator
Fawning due date and window from breeding.
DNA Complement Calculator
DNA complement, length, and GC percent.
DNA GC Content Calculator
GC percent, base counts, and Wallace melting temp from a DNA sequence.
Dog Age Calculator
Your dog's age in human years by size, plus life stage.
Dog Chocolate Toxicity Calculator
Chocolate dose in mg per kg from dog weight, type, and amount eaten.
Dog Food Calculator
Daily calories and cups from weight, life stage, and food energy.
Dog Pregnancy Calculator
Due date, whelping window, and vet checks from mating date.
Dog Treat Calculator
Treat calories and count from dog weight, 10% rule.
Dog Xylitol Toxicity Calculator
Xylitol dose in g per kg from dog weight, pieces, and label mg.
Egg Incubation Calculator
Hatch date, lockdown, and candling dates for poultry eggs.
Garden Harvest Calculator
Turn plants, fruits each, and harvest weeks into totals and weekly pace.
Germination Test Calculator
Seed germination percent, verdict, and sowing multiplier from sprouted count.
Goat Gestation Calculator
Kidding due date from breeding date, with window and prep milestones.
Goldfish Tank Calculator
Minimum goldfish tank gallons and weekly changes.
Growing Degree Days Calculator
Daily corn heat units and season progress from high, low, and maturity target.
Growing Season Calculator
Frost-free days and succession rounds from two frost dates.
Guinea Pig Diet Calculator
Guinea pig pellets and veg from pig count.
Hamster Wheel Size Calculator
Hamster wheel and cage PASS/FAIL vs minimums.
Honey Harvest Calculator
Total pounds from hive count and yield.
Horse Feed Calculator
Daily hay and grain from horse weight and workload.
Horse Gestation Calculator
Foaling due date and normal window from breeding date, at 340 days.
Horse Water Calculator
Horse daily gallons from weight and workload state.
Hummingbird Nectar Calculator
Sugar water batches at 1 to 4 ratio, with change schedule.
Mason Bee House Calculator
Tube count, bore size, and mounting height for mason bee houses.
Pig Gestation Calculator
Farrowing due date and window from breeding date.
Pond Stocking Calculator
Pond fish counts per acre with 10 to 1 balance and seasonal schedule.
Punnett Square Calculator
Genotype and trait odds for one gene from two parent genotypes.
Purple Martin House Calculator
Martin rooms, holes, and mounting height.
Rabbit Diet Calculator
Rabbit pellets and greens from body weight.
Rabbit Gestation Calculator
Kindling due date from breeding date, with nest box day.
Seed Starting Date Calculator
Indoor sow and transplant dates from last frost and crop.
Sheep Gestation Calculator
Lambing due date and window from breeding date.
Soil Texture Calculator
USDA texture class from sand, silt, and clay percents.
Tree Age Calculator
Estimate tree age from trunk size at 4.5 ft with species growth factors.
Tree Watering Calculator
Weekly tree water from trunk diameter.
Turtle Tank Size Calculator
Minimum turtle tank gallons and depth from shell.
Worm Bin Calculator
Worm pounds and bin size from weekly food scraps.