Estimación vs. cálculo vs. presupuesto

In Spanish, 'estimación', 'cálculo' and 'presupuesto' are terms often used in the context of assessing quantities or anticipating costs. While they can be similar, they have distinct nuances that are important to understand, especially for proper usage in financial and planning scenarios.

Estimación

'Estimación' refers to an approximate calculation based on judgment or experience, without necessarily using precise data or strict mathematical methods. It gives a general idea or opinion about the value, size, cost or other aspects of something.
Mi estimación es que el proyecto tardará al menos tres meses en completarse.
(My estimate is that the project will take at least three months to complete.)
La estimación de la población de la ciudad fue realizada por expertos demográficos.
(The population estimate of the city was made by demographic experts.)

Cálculo

'Cálculo' means a more precise calculation or mathematical determination of numbers. It involves specific formulas, measurements and numbers and is often used in contexts where accuracy is important.
El cálculo de los ingresos trimestrales muestra un aumento del 5%.
(The calculation of the quarterly revenues shows a 5% increase.)
Necesitamos un cálculo exacto del material necesario para la construcción.
(We need an exact calculation of the material needed for the construction.)

Presupuesto

'Presupuesto' refers specifically to a budget or an estimation of the expected income and expenditure for a particular period or project. It is often detailed and includes itemized costs and financial planning elements.
El ayuntamiento tiene un presupuesto limitado para las fiestas de fin de año.
(The city council has a limited budget for the end-of-year festivities.)
Para iniciar el proyecto necesitamos aprobar primero el presupuesto del departamento financiero.
(To start the project we first need to approve the financial department's budget.)

Summary

In summary, while all three terms can be used in relation to conclusions about future quantities or values, 'estimación' is less formal and less precise than 'cálculo', which implies a specific mathematical process. 'Presupuesto', on the other hand, is specifically linked to financial contexts and reflects an itemized plan of income and expenditure rather than just a numerical forecast or estimate.