CIVORA · Design slope

Slope & offset

Enter the crest level, the toe level and the design slope. The horizontal offset, slope length and the level at any point on the batter update as you type.

Design levels

Crest / start level m

Toe / target level m

Design slope

Slope given as

Horizontal H

Vertical V

Point on the batter

Horizontal distance from crest x, m

Find distance to level m

Distance along slope face m

Cross-section, vertical scale exaggerated to fit.

Slope converter

Type into any field and the others follow. Use this to move between drawing ratios, percent grades and angles.

Percent %

Angle decimal °

Angle d m s

1V : n H n

1H : n V n

Per mille ‰

Radians

Rise over run m per 1 m

Reference

Gradient g
g = V ÷ H = tan θ

Percent
% = g × 100

Angle
θ = atan(g) · 180/π

Ratio 1V : nH
n = 1 ÷ g = H ÷ V

Per mille
‰ = g × 1000

Slope length
L = √(H² + V²) = H ÷ cos θ

Common batter	%	Angle °	Gradient

Coordinates

Grid bearings are measured clockwise from grid north. Angles accept decimal degrees or d m s, for example 121 56 30.32.

Start X / Easting

Start Y / Northing

Bearing ° or d m s

Distance m

Point A X

Point A Y

Point B X

Point B Y

Level A optional

Level B optional

Line start X

Line start Y

Line end X

Line end Y

Set out a point

Chainage along line m

Offset + right, − left

Check a point

Point X

Point Y

Plan view. Right is to the right when looking from start to end.

Grade profile

Straight-grade levels between two points, split into equal segments or a fixed interval. Copy the table straight into Excel or a CAD script.

Start chainage m

Total distance m

Start level m

End level m

Split by

Segments

Level at chainage m

Long section, vertical scale exaggerated.

#	Chainage	Distance	Level

Trigonometry

Solve any right-angled or oblique triangle from the values you know. Every result shows the formula used.

Known values

Opposite height, a

Adjacent base, b

Hypotenuse c

Angle θ ° or d m s

θ sits between the adjacent side and the hypotenuse.

Known values

Side a is opposite angle A, b opposite B, c opposite C.

Drawn to scale.

SOH
sin θ = Opposite ÷ Hypotenuse

CAH
cos θ = Adjacent ÷ Hypotenuse

TOA
tan θ = Opposite ÷ Adjacent

Pythagoras
c² = a² + b²

Sine rule
a ÷ sin A = b ÷ sin B = c ÷ sin C

Cosine rule
a² = b² + c² − 2bc·cos A

Area
½·a·b·sin C, or Heron: √(s(s−a)(s−b)(s−c))

Angle sum
A + B + C = 180°

Reciprocals
cosec = 1/sin, sec = 1/cos, cot = 1/tan

Identity
sin²θ + cos²θ = 1

Degrees to radians
rad = deg × π ÷ 180

Slope link
tan θ = V ÷ H, so 1:15 → θ = 3.814°

Function calculator

Angle or value

Input unit

Chainage labels

Builds one AutoCAD / BricsCAD -TEXT command per chainage. Paste into the command line or save as a .scr and run with SCRIPT.

Prefix

Start chainage m

End chainage m

Chainage interval m

First insertion X

X spacing drawing units

Insertion Y

Y spacing optional

Text height

Rotation °

Justify

Chainage decimals

About

CIVORA

Civil Infrastructure, Volume, Offshore & Reclamation Analytics. A free set of design calculators for engineers, surveyors and data processors working on marine, dredging, reclamation and civil infrastructure projects.

What it does

CIVORA turns the everyday hand calculations of design and survey work into live tools. Change any input and every result, drawing and formula updates at once, so you can check a batter, set out a point or label a long section in seconds.

Slope & offset
Toe offset, slope-face length, level at any distance and distance to any level.

Slope converter
Percent, degrees, d m s, 1V:nH ratios, per mille and radians.

Coordinates
Bearing and distance, inverse, and chainage-offset setting-out.

Grade profile
Interpolated levels by segments or interval, ready for Excel.

Trigonometry
Right and oblique triangle solvers with every formula shown.

Chainage labels
AutoCAD / BricsCAD -TEXT scripts for long-section labelling.

Method and good practice

All results are computed in your browser. No data is uploaded or stored on a server. Bearings are grid bearings clockwise from north. Slopes are straight grades between two levels, and triangle solutions use the sine and cosine rules.

Always check critical design values independently before issue. CIVORA is a calculation aid and does not replace project specifications, design reviews or professional sign-off.

Developer

Mahésh M Mohanan is a Senior Survey Data Post Processor with 19 years of experience across more than 15 countries. His work covers hydrographic data processing, 3D seabed modelling, dredging and reclamation, subsea rock installation, pipeline surveys and offshore wind projects.