Marine Mean Draft Calculator
Calculate the arithmetic average of forward and aft draft readings without vessel-specific corrections.
Inputs
Updates as you typeResults
Mean draft
| Forward draft | 7.8 m |
|---|---|
| Aft draft | 8.5 m |
| Trim · AFT − FWD | 0.7 m |
| Trim condition | Trim by Stern |
Overview
Calculate the arithmetic average of forward and aft draft readings without vessel-specific corrections.
Formula
Tmean = (TFWD + TAFT)/2 ΔT = TAFT − TFWD
Example
How to use
- Check the units, enter the required values and select the available calculation options.
- Results update immediately. Correct any highlighted input before using the result.
- Choose display precision, copy the result or share the current inputs. Reset restores the example values.
Engineering notes
- A two-point mean is not necessarily the measured midship draft or a corrected hydrostatic draft.
- Draft-mark offsets, heel, hogging/sagging and density corrections require the appropriate vessel procedures.
Frequently asked questions FAQ
What if the vessel is hogging or sagging?
Two readings alone cannot describe hull deformation. Include midship and port/starboard observations and apply the vessel's approved corrections.
Does display precision change the calculation?
No. Rounding is applied only to displayed results, not intermediate calculations. Small nonzero values use scientific notation. Consider the precision of the original measurements when interpreting results.
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