Free aquarium & pet calculators

Practical numbers for better everyday decisions.

Estimate aquarium volume, substrate, weight, equipment needs, maintenance, and everyday dog and cat costs—with formulas and limits explained.

Start with tank volume Estimate pet costs

Aquarium toolkit Start with what you can measure. Use each result in the next decision.

01 MeasureVolume, substrate & weight 02 PlanSetup, filter & heater 03 MaintainWater changes, dosing & cost

Choose by task

What are you working out today?

Skip the library and go straight to the small group of tools that fits your decision.

12 aquarium calculators

Build a tank plan from real measurements

Start with volume, then reuse that number for substrate, weight, equipment, maintenance, and running cost.

Setup & sizing

Measure before you buy

Tank Volume Calculator Real water volume after substrate and waterline gap. Substrate Calculator Volume, weight, slope, buffer, and whole bags. Aquarium Weight Calculator Water, glass, substrate, hardscape, stand, and equipment. Setup Cost Calculator Build a realistic startup budget category by category.

Maintenance & equipment

Use volume in the next decision

Water Change Calculator Know how much water to remove and replace. Filter Flow Calculator Estimate turnover after real-world flow loss. Heater Wattage Calculator Estimate heater size from volume and temperature difference. Dosing Calculator Scale a product label dose to actual water volume. Electricity Cost Calculator Estimate monthly and yearly equipment running cost.

Planted tanks & cautious starting points

Use the estimate, then observe the tank

Light Timer Calculator Plan a starting photoperiod around plants and algae pressure. CO₂ Bubble Rate Calculator Get a cautious starting point—not a safety guarantee. Stocking Guideline Calculator Review a cautious range before species-specific research.

Dog & cat cost tools

Turn package prices into a monthly budget

These tools compare costs only. They do not recommend diets, medical care, or insurance products.

Pet Monthly Cost Calculator Food, litter, supplies, grooming, insurance, and vet budget. Dog Food Cost Calculator Daily, monthly, and yearly cost from your own feeding amount. Cat Food Cost Calculator Compare package price, feeding amount, and number of cats. Cat Litter Cost Calculator Estimate recurring cost from package size and weekly use. Dog Treat Cost Calculator See what a treat routine adds up to over a month or year. Insurance vs Emergency Fund Compare your own quote and savings scenario—not financial advice.

Numbers with context

Useful estimates, without pretending they are guarantees.

Start with your inputs.We use the measurements, prices, and product-label figures you provide.

Show the assumptions.Each calculator explains what is included, what is estimated, and what can change the result.

Keep the boundary clear.Care, safety, structural, medical, and financial decisions still need appropriate expert judgment.

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