Useful Tools for Fish Keepers. Make Aquarium Care Easy

Keeping fish can be rewarding, but maintaining a healthy aquarium requires careful planning and accurate measurements. To help hobbyists of all levels, we’ve created a suite of practical, easy-to-use tools for fish keeping. These calculators take the guesswork out of everyday aquarium tasks, helping you measure tank volume, plan substrate, and make informed decisions for the wellbeing of your fish and plants.

Useful Tools for Fish Keepers. Make Aquarium Care Easy

Keeping fish can be rewarding, but maintaining a healthy aquarium requires careful planning and accurate measurements. To help hobbyists of all levels, we’ve created a suite of practical, easy-to-use tools for fish keeping. These calculators take the guesswork out of everyday aquarium tasks, helping you measure tank volume, plan substrate, and make informed decisions for the wellbeing of your fish and plants.

Aquarium Volume Calculator

Simply enter the length, width, and height of your aquarium to instantly calculate its total capacity. You can also adjust the water fill level to account for the gap at the top of the tank, ensuring a more precise result. Understanding your true water volume is fundamental to successful fish keeping. It informs every critical decision, from selecting the correctly rated filter and heater to planning safe stocking levels and regular water changes. Whether you are maintaining a vibrant planted aquascape, a tropical community, or a cold-water setup, accurate measurements help you provide a stable and healthy environment for your livestock.

Volume Calculator

How to measure tank dimensions

Take measurements across the primary outer frame dimensions to isolate total physical capacity boundaries accurately.

Length Width Height
Tip: Always measure the internal space if your tank features exceptionally thick custom glass or internal filter partitions.
0 Litres

Total aquarium water capacity

Aquarium Substrate Calculator

Simply enter the length, width, and desired depth of your substrate to instantly calculate the total volume required. You can also account for different layouts, whether you prefer a uniform flat bed or a more dynamic sloped aquascape, to ensure a precise estimate. Selecting the correct amount of substrate is fundamental to both the visual appeal and biological success of your setup. It provides the necessary foundation for plant roots to thrive and creates a natural, stable environment for bottom-dwelling species. Whether you are working with a compact nano tank or a large display aquarium, accurate substrate planning ensures you have exactly what you need to build a healthy and balanced home for your fish.

Substrate Calculator

Substrate depth planning

Planning proper substrate bed depth depends entirely on whether you are maintaining live aquatic plants or simple decorations.

Bed Depth
Tip: Aim for a standard 4 cm to 5 cm depth bed to allow heavy-rooting plants like Amazon Swords or Crypts to thrive comfortably.
0 kg

Approximate sand/gravel required

Substrates and Bonding Agents

Now you know how much substrate you need, you can purchase it here. You can also pick up your bonding agents.

Rectangular Pond Calculator

Simply enter the length, width, and depth of your rectangular pond to instantly calculate its total capacity in both Litres and UK Gallons. You can select your preferred measurement metric for each input to ensure a seamless setup, providing a highly precise volume result for your layout.Understanding your true water volume is fundamental to successful pond keeping. It informs every critical decision, from selecting the correctly rated filtration system and UV clarifier to planning safe fish stocking levels and calculating accurate water treatments or treatments for blanketweed. Whether you are maintaining a dedicated Koi pond, a vibrant planted water garden, or a haven for native wildlife, accurate measurements help you provide a stable and healthy ecosystem for your livestock.

Rectangular Pond Calculator

How to measure your rectangular pond

For accurate volume planning, ensure you measure the maximum internal dimension points of the pond liner shell.

Length Width Depth
Tip: If your pond has shelving or sloping sides, measure the average depth rather than the deepest point to avoid overestimating volume.
0 L

Total pond capacity in Litres

0 Gal

Total pond capacity in UK Gallons

Round Pond Calculator

Simply enter the diameter and depth of your circular pond to instantly calculate its total capacity in both Litres and UK Gallons. You can select your preferred measurement metric for each input to ensure a seamless setup, providing a highly precise volume result for your layout.Understanding your true water volume is fundamental to successful pond keeping. It informs every critical decision, from selecting the correctly rated filtration system and UV clarifier to planning safe fish stocking levels and calculating accurate water treatments or treatments for blanketweed. Whether you are maintaining a dedicated Koi pond, a vibrant planted water garden, or a haven for native wildlife, accurate measurements help you provide a stable and healthy ecosystem for your livestock.

Round Pond Calculator

How to measure your round pond

For circular layouts, you need the distance across the widest continuous centerline alongside total depth.

Diameter Depth
Tip: Measure across the absolute centre point from water edge to water edge to find the proper diameter value.
0 L

Total pond capacity in Litres

0 Gal

Total pond capacity in UK Gallons

Pond Liner calculator

Simply enter the approximate length, width, and depth of your planned garden pond to instantly calculate the total minimum liner dimensions required. You can toggle between different input metrics and select your preferred output unit to ensure you find a precise match for commercial roll sizes.Working out just how much pond liner you will need to completely line a dug garden profile can be challenging. It requires calculating the base surface area alongside double the maximum vertical depth measurements to handle the drop walls safely. Our tool automatically accounts for a safety border overlap margin, ensuring you retain enough extra material to seamlessly anchor the sheet below perimeter stone or soil borders without running short during installation.

Pond Liner Calculator

Liner Sizing Guidance

Liner dimensions require calculating the base width and length plus double the maximum depth, alongside a mandatory edge overlap for anchoring.

Base Width Overlap Depth
Note: Our calculator dynamically embeds a secure 50 cm (1.6 feet) border overlap value into your final results automatically.
0 m

Minimum Liner Length Required

0 m

Minimum Liner Width Required

Why Aquarium Volume Matters

Why Aquarium Volume Matters

While many aquariums are labelled with a nominal capacity, the actual amount of water your tank holds often varies once you account for substrate, decor, and equipment displacement. By accurately calculating the true volume, you can make far more informed decisions regarding filtration, heating, and safe stocking levels.Establishing your tank’s precise capacity is also critical when dosing water conditioners, fertilisers, or medicinal treatments. Since most aquarium products are formulated for specific volumes, knowing the true quantity of water helps you maintain an effective environment and prevents the risks associated with under-dosing or accidental overdosing.
How to Measure Your Fish Tank

How to Measure Your Fish Tank

To calculate the water volume of a rectangular aquarium, measure the length, width, and height of the tank in centimetres. Enter these dimensions into the calculator and adjust the fill level to reflect the actual water line of your setup. For the most accurate results, we recommend measuring the internal dimensions of the glass where possible, while also accounting for the displacement caused by substrate, rockwork, and decorations. It is also important to note that most aquariums sit with a small gap between the water surface and the top rim. The tool will automatically convert your measurements into both litres and gallons, providing a precise estimate of your aquarium's total capacity.
Use Your Tank Volume for Better Fish Keeping

Use Your Tank Volume for Better Fish Keeping

Once you have established your aquarium's precise volume, you can use that data to make far more informed decisions regarding your setup. Accurate capacity measurements directly influence your filtration requirements, heating efficiency, and the specific number of fish your ecosystem can safely support. This knowledge also simplifies your routine maintenance; when performing water changes, for example, you can easily calculate the exact amount of water to be replaced, ensuring your aquarium remains a stable and healthy environment for your livestock.
Why Substrate Volume Matters

Why Substrate Volume Matters

Once you have established your aquarium's precise volume, you can use that data to make far more informed decisions regarding your setup. Accurate capacity measurements directly influence your filtration requirements, heating efficiency, and the specific number of fish your ecosystem can safely support. This knowledge also simplifies your routine maintenance; when performing water changes, for example, you can easily calculate the exact amount of water to be replaced, ensuring your aquarium remains a stable and healthy environment for your livestock.
How to Use the Calculator

How to Use the Calculator

To determine your substrate requirements, simply enter your tank’s length and width before choosing between a flat or sloped aquascape layout. After entering your desired depth, the tool will instantly calculate the volume in litres, the approximate weight in kilograms, and the estimated number of bags needed for your project. We recommend measuring the internal dimensions of your aquarium for the most precise results, while also accounting for any large rocks or ornaments that may reduce the total volume required. You should also consider adjusting the depth based on your specific plant types, as species with larger root systems often require deeper layers to thrive. By calculating these requirements in advance, you can ensure you purchase exactly what you need to create a beautifully prepared and stable environment for your fish and plants.
Why Volume Matters

Why Volume Matters

Tank labels ignore substrate and decor displacement. Knowing your precise volume is vital for accurate filtration, heating, safe stocking, and correct chemical dosing.
How to Measure Tanks

How to Measure Tanks

Measure your tank's internal length, width, and height in centimetres. Input these dimensions, adjusting for your water line and internal displacement.
Better Fish Keeping

Better Fish Keeping

Knowing your true volume ensures correct filtration, heating, and stocking levels. It also streamlines routine maintenance, allowing for precise water changes and chemical dosing to keep your ecosystem stable.
Substrate Volume

Substrate Volume

Knowing your true volume ensures correct filtration, heating, and stocking. It simplifies routine maintenance, allowing for precise water changes to keep your ecosystem stable and healthy.
How to Use Calculator

How to Use Calculator

Enter your tank dimensions and desired depth for a flat or sloped layout. Our calculator determines the volume, weight, and bags required, accounting for displacement.