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Calcrivo

RNN Parameters Calculator

Calculate the number of trainable parameters in a recurrent neural network layer.

Inputs

Total Parameters

394,240

Input Weights

131,072

Hidden Weights

262,144

Step by step

  1. Input→Hidden weights: input × hidden

    256 × 512

    = 131,072

  2. Hidden→Hidden weights: hidden × hidden

    512 × 512

    = 262,144

  3. Biases (input + hidden)

    2 × 512

    = 1,024

  4. Total

    131072 + 262144 + 1024

    = 394,240

How it works

A vanilla RNN layer has two weight matrices: W_ih (input to hidden, size input×hidden) and W_hh (hidden to hidden, size hidden×hidden), plus two bias vectors of size hidden. Total = input×hidden + hidden² + 2×hidden.

Formula

RNN Parameters

params = input_size × hidden_size + hidden_size^2 + 2 × hidden_size

input_size
Dimensionality of input features
hidden_size
Dimensionality of hidden state

Frequently Asked Questions

How do LSTM parameters compare to vanilla RNN?

LSTMs have 4× the parameters of a vanilla RNN because they have four gate matrices (input, forget, cell, output) instead of one.

Why does hidden size dominate parameter count?

The hidden-to-hidden matrix is h×h, which grows quadratically. For large hidden sizes (512+), this dominates total parameters.

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