# DWT Calculator — Free vessel calculator > Calculate DWT (carrying capacity) from displacement and lightship weight, and the cargo capacity left after fuel, water and stores. - URL: https://demo.fcrsoft.com/en/maritime/dwt-calculator - Language: en - Updated: 2026-10-03 - Publisher: FCRSOFT (https://fcrsoft.com) [Demos](https://demo.fcrsoft.com/?hl=en) / [Free Tools](https://demo.fcrsoft.com/en/tools) / [Maritime Calculators](https://demo.fcrsoft.com/en/maritime) / DWT Calculator Free tool # DWT Calculator Calculate DWT (carrying capacity) from displacement and lightship weight, and the cargo capacity left after fuel, water and stores. No sign-up needed; results update as you type. [See the system that does this automatically Open the live demo](https://demo.fcrsoft.com/login.php?package=fleet) ## Calculator Displacement : 67900 t Lightship weight : 10500 t Fuel, fresh water, stores and constant : 2400 t This calculator runs in your browser; the data you enter is not stored. ## Results DWT 57,400 t Cargo capacity 55,000 t DWT / displacement 84.5 % **Keep Your Fleet and Vessel Data in One Place**Result: **57,400**. FCRSOFT stores DWT, TPC and draft data on vessel cards and uses it automatically in voyage estimates. [Open the live demo](https://demo.fcrsoft.com/login.php?package=fleet) [Request a demo](https://fcrsoft.com/en/contact/) ## DWT Calculator: what you need to know DWT (deadweight) is the total weight a ship can carry down to its load line, including cargo, fuel, fresh water, stores and constants. It is displacement minus lightship weight; real cargo capacity is smaller than DWT. **Expert tip:** If a port or canal draft limit is below summer draft, the cargo you can take falls; deduct the difference × 100 × TPC from your plan. ## DWT Calculator: worked example Example values: Displacement 67,900 t, Lightship weight 10,500 t, Fuel, fresh water, stores and constant 2,400 t. With these values the results are: | DWT | 57,400 t | | Cargo capacity | 55,000 t | | DWT / displacement | 84.5 % | ### How to use: DWT Calculator - Enter your own values: Displacement, Lightship weight, Fuel, fresh water, stores and constant. - Results are calculated as you type: DWT, Cargo capacity, DWT / displacement. - Check every step of the calculation in the formulas below. ## How is it calculated? - **DWT** = [Displacement] − [Lightship weight] - **Cargo capacity** = [DWT] − [Fuel, fresh water, stores and constant] - **DWT / displacement** = [DWT] ÷ [Displacement] × 100 Ship calculations are estimates based on standard formulas. Loading, stability and draft decisions must be based on the ship’s approved documents and loading computer. ## Other tools running on Vessel Hydrostatics Engine Calculates DWT, displacement, draft, trim, TPC and MCT relationships with standard naval formulas; results must be checked against approved vessel data. - [Displacement Calculator](https://demo.fcrsoft.com/en/maritime/displacement-calculator) - [Lightship Weight Calculator](https://demo.fcrsoft.com/en/maritime/lightship-weight-calculator) - [Cargo Capacity Calculator](https://demo.fcrsoft.com/en/maritime/cargo-capacity-calculator) - [Cargo Intake Calculator](https://demo.fcrsoft.com/en/maritime/cargo-intake-calculator) - [DWT Utilization](https://demo.fcrsoft.com/en/maritime/dwt-utilization-calculator) - [Draft Calculator](https://demo.fcrsoft.com/en/maritime/draft-calculator) - [Mean Draft Calculator](https://demo.fcrsoft.com/en/maritime/mean-draft-calculator) - [Forward / Aft Draft Calculator](https://demo.fcrsoft.com/en/maritime/forward-aft-draft-calculator) - [Trim Calculator](https://demo.fcrsoft.com/en/maritime/trim-calculator) - [Trim by Stern (Loading Effect)](https://demo.fcrsoft.com/en/maritime/trim-by-stern-calculator) - [Freeboard Calculator](https://demo.fcrsoft.com/en/maritime/freeboard-calculator) - [TPC Calculator](https://demo.fcrsoft.com/en/maritime/tpc-calculator) FCRSOFT ## FCRSOFT does this for you automatically You don’t need to do the calculations and checks on this page by hand every day. FCRSOFT derives them all automatically from the records entered in the field. - DWT, TPC, draft and capacity data are stored on vessel cards. - Certificate and document expiry dates are tracked, with warnings before they lapse. - Voyage estimates use vessel data automatically. [Open the live demo](https://demo.fcrsoft.com/login.php?package=fleet) [Explore the Fleet & Vessel package](https://demo.fcrsoft.com/demo/fleet?hl=en) [demo.fcrsoft.com](https://demo.fcrsoft.com/login.php?package=fleet) ## Frequently asked questions How is DWT Calculator calculated? Calculate DWT (carrying capacity) from displacement and lightship weight, and the cargo capacity left after fuel, water and stores. The calculation uses Vessel Hydrostatics Engine: Calculates DWT, displacement, draft, trim, TPC and MCT relationships with standard naval formulas; results must be checked against approved vessel data. DWT Calculator: what is it and when is it used? DWT (deadweight) is the total weight a ship can carry down to its load line, including cargo, fuel, fresh water, stores and constants. It is displacement minus lightship weight; real cargo capacity is smaller than DWT. DWT Calculator: what should I watch out for? If a port or canal draft limit is below summer draft, the cargo you can take falls; deduct the difference × 100 × TPC from your plan. How is DWT found? DWT = [Displacement] − [Lightship weight]. With the example values (Displacement 67,900 t, Lightship weight 10,500 t, Fuel, fresh water, stores and constant 2,400 t) the result is 57,400 t. How is Cargo capacity found? Cargo capacity = [DWT] − [Fuel, fresh water, stores and constant]. With the example values (Displacement 67,900 t, Lightship weight 10,500 t, Fuel, fresh water, stores and constant 2,400 t) the result is 55,000 t. Worked example: DWT Calculator Example values: Displacement 67,900 t, Lightship weight 10,500 t, Fuel, fresh water, stores and constant 2,400 t. DWT: 57,400 t; Cargo capacity: 55,000 t; DWT / displacement: 84.5 %. Is DWT Calculator free? Yes. The tool is free, needs no sign-up and runs in your browser; the data you enter is not stored. Can FCRSOFT do this calculation automatically? FCRSOFT stores DWT, TPC and draft data on vessel cards and uses it automatically in voyage estimates. You can try the Fleet & Vessel package in the live demo without installing anything. Do the results replace official ship calculations? No. Ship calculations are estimates based on standard formulas. Loading, stability and draft decisions must be based on the ship’s approved documents and loading computer. ## Related tools and guides [Free tool ### Displacement Calculator Calculate a ship’s volume and weight displacement from length, breadth, draft, block coefficient and water density. Open the tool](https://demo.fcrsoft.com/en/maritime/displacement-calculator) [Free tool ### Lightship Weight Calculator Calculate lightship weight and its share of displacement from summer displacement and DWT. Open the tool](https://demo.fcrsoft.com/en/maritime/lightship-weight-calculator) [Free tool ### Cargo Capacity Calculator Deduct fuel, fresh water, stores, residual ballast and constant from DWT to calculate the net cargo you can carry. Open the tool](https://demo.fcrsoft.com/en/maritime/cargo-capacity-calculator) [Free tool ### Deadweight Scale Calculate displacement and DWT at an observed draft by linear interpolation between light and summer conditions. Open the tool](https://demo.fcrsoft.com/en/maritime/deadweight-scale)