Calculator sources & credits

LoschaZ wrote this workspace, expression parser, helpers, graph interactions and interface for this website.

Decimal arithmetic

The calculator uses decimal.js 10.6.0 by MikeMcl and contributors, distributed under its MIT license. It is self-hosted; no calculation is sent to a third-party API. The engine uses 40 significant digits internally, with shorter display rounding and practical input limits.

The MIT Licence.

Copyright (c) 2025 Michael Mclaughlin

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Models and limits

Percentages use explicit base amounts. Unit factors are fixed definitions; temperature offsets are handled separately. Calendar arithmetic uses UTC date components. Loan estimates use a fixed-rate amortization model with monthly rounding. Graph values use JavaScript floating-point arithmetic and finite sampling, so discontinuities or very small features can be missed. This is a practical browser tool, not a proof system.