Engineering formula book for metalwork, electrical engineering and mechanics
A formula book shows you the formula. Gesello also works it out. You enter what you know and get the quantity you are looking for with sketch, formula and calculation steps. If you are missing a different quantity, Gesello rearranges the formula itself.
- 50+Calculations with calculation steps
- 8Topics from areas to heat
- 0 €free, no ads
What’s inside
Over 50 calculations in eight topics. Each calculation comes with the formulas for reference, already rearranged into the usual forms.
Areas
Rectangle, square, triangle, trapezium, parallelogram, rhombus, circle, annulus, ellipse and regular polygon – with area, perimeter and diagonal.
A = π · r²
Solids
Cube, cuboid, cylinder, tube, cone, truncated cone, pyramid, sphere and spherical cap – volume, surface area and the mass for the selected material.
m = V · ρ
Circle and arc
Arc length, chord, arc height, circular sector and circular segment. Two known values give you the rest, including the radius from chord and arc height.
b = π · d · α360°
Percentages and rule of three
Percentage calculation, percentage change, rule of three for direct and inverse proportion, interest and compound interest.
W = G · p100
Electrical engineering
Formula wheel for U, I, R and P, series and parallel circuits, cables and voltage drop, AC and three-phase power, efficiency and electricity costs.
U = R · I
Mechanics and motion
Weight force, combining and resolving forces, inclined plane, friction, torque, lever, pulley block, work and power, motion and transmission ratio.
M = F · r
Angle
Converting degrees, radians and gradians, degrees, minutes and seconds, plus sine, cosine and tangent on the unit circle.
1 rad = 180°π
Heat
Linear and volumetric expansion, joining temperature for shrink fits, quantity of heat and heating time.
Δl = α · l₀ · Δt
More than a reference
The formula rearranges itself
You choose what you are looking for and enter what you know. Gesello takes the right form of the formula and works it out. The unknown quantity is marked orange in the picture.
- In reverse tooIf a basic quantity is missing, Gesello calculates it back from the result, for example the diameter from the area. A check confirms the value.
- Calculation steps with your numbersEvery step with the values filled in, fractions as real fractions.
- Sketch and legendEvery calculation has a dimensioned sketch. All formula symbols are listed with name and unit.
Made for the workshop
With materials and guide values
For solids you choose the material and get the mass straight away. Typical values such as density or expansion coefficient are just a tap away instead of a search.
- Found quicklyThe search finds calculations such as compound interest or formula wheel, even with workshop words.
- Copy and shareYou copy or share results with one tap, as text with a link.
- No internet neededGesello calculates on your device, on the shop floor just as well as on site.
For college and exams
Practice with worked solutions
In the Practice module you solve workshop exercises yourself. Gesello checks your result and shows the worked solution. That way the formula sticks when it matters.
Question in, answer out
Typical tasks from the workshop and vocational college, and what Gesello calculates for them.
Joining temperature with an assembly clearance of 50 µm and a room temperature of 20 °C. Gesello takes the interference directly from the fit. Densities and expansion coefficients are guide values.
The Technical mathematics module
Technical mathematics
FreeOver 50 calculations, also in reverse.
Areas, solids, circular arcs, percentages, forces and electrical engineering: you enter what you have, Gesello calculates the rest. Every calculation has a dimensioned sketch and the calculation steps.
- Areas and solids
From rectangle to spherical segment, solids with mass. - Circle and arc
Radius on the workpiece from chord and height. - Electrical engineering
Formula wheel, circuits, power and electricity costs. - Mechanics
Forces, levers, friction, power, motion. - Heat
Expansion and joining temperature for shrink fitting.
Also in the module
- Percentages, rule of three, interestBasic calculations for work and everyday life, also with compound interest.
- Angles and unit circleDegrees, radians, gradians and sin, cos, tan by dragging on the circle.
- Cables and three-phase currentVoltage drop, AC and three-phase power, efficiency.
- Joining temperature with fitTake the interference directly from a fit such as H7/s6.
- Quantity of heat and heating timeHow much energy and time heating takes.
- Radius or diameterCircle and annulus optionally with radius, interest also by days.
- Search with workshop termsFinds calculations as you type, even with synonyms and typos.
- Formulas for referenceFor each calculation, the rearranged formulas with a legend of the symbols.
An arc segment is missing its radius. You measure a chord of 80 mm and a height of 10 mm.
s 80h 10- Radius
- 85 mm
- Central angle
- 56,1°
- Arc length
- 83.3 mm
Formulas in the specialist modules too
Many formulas are built right into the specialist modules. There you keep calculating with table values and guide values from the workshop.
Frequently asked questions
Does Gesello replace a printed formula book?
In everyday work, mostly yes. Gesello has the formulas on board, rearranges them and works them out. In exams, however, the exam regulations decide. Phones are usually not allowed there, but a printed formula book or technical handbook often is. So also practise with the book that is permitted in your exam.
What does the formula book cost?
Nothing. Technical mathematics, Triangles, Units and Practice are among the free basic modules. You unlock the calculator and specialist modules such as Bending or Hydraulics with Gesello Pro.
Does it work without internet?
Yes. Gesello calculates directly on your device, on the shop floor just as well as on site.
How accurate are the results?
Gesello uses the same formulas you find in printed formula books. Material properties such as density or expansion coefficient are guide values. The drawing, the manufacturer’s data and your company’s specifications always take precedence.