Effect Size Calculator for Cohen's d (Updated September 2014)
 This spreadsheet contains calculators that produce Cohen's d, rsquared, Hedge's g, and Glass's delta as measures of effect size for the difference between two means. Can be used with single samples (t or z), independent samples, and paired samples.
 September 2014: switched calculations for r to r squared and added all formulas to the spreadsheet. Now you can see exactly what calculations are being done.
Normal Distribution Table
 This spreadsheet contains a table of zscores with their corresponding areas under the curve (from the mean to z, and from z to infinity). There are also calculators to determine specific areas for any zscore, and the zscores that correspond to various areas.
T Distribution Table (Updated September 2014)
 This spreadsheet contains a table of critical tscores for various degrees of freedom at various levels of alpha, for 1 or 2tailed distributions. There are also calculators to determine exact critical tscores for any level of alpha at any sample size, as well as any pvalue for a tscore at any sample size. This spreadsheet also includes the Effect Size Calculator.
 September 2014: updated formulas in the effect size portion of the spreadsheet.
Critical Pearson's r Values
 This spreadsheet contains a table of the critical Pearson's r values needed to obtain statistical significance at various alphas and sample sizes. There are also calculators to determine a specific correlation coefficient at any alpha at any sample size, as well as the pvalue for any correlation coefficient at any sample size.
F Distribution Table
 This spreadsheet contains tables of critical Fratios at alpha=.05 and alpha=.01 for various degrees of freedom of the numerator and denominator. There are also calculators to determine an exact critical Fratio with any degrees of freedom at any alpha, and an exact pvalue for any Fratio at any degrees of freedom.
Chi Square Distribution Table and Calculator (Updated September 2014)

This spreadsheet contains

A table of critical chi square values for various degrees of freedom at various levels of alpha for various degrees of freedom.

Calculators to determine exact critical chi square values at any alpha and degrees of freedom, as well as the pvalue for any chi square value at any degrees of freedom.
 Calculators that automatically produce chi square values and pvalues from observed frequencies for 1x2, 1x3, 2x2, 2x3, 3x2, and 3x3 contingency tables. The calculators display expected frequencies and graphs of the proportions of responses across either columns or r
 September 2014: fixed a bug that prevented the calculator from displaying all chi square values. Now works like a charm.