Enter figures for parties’ vote shares in Wales using the boxes to the left, then click "calculate results" to see the predicted outcome.
It is best to fill in all the boxes, but not necessary. Any box you leave blank will remain unchanged from the 2001 position.
The 2001 share of the vote in Wales was approximately Labour 49%, Conservative 21%, Plaid Cymru 14%, Liberal Democrat 14% and others 2%.
The calculator uses a formula that works best with realistic figures rather than extremes that are unlikely to happen - for example a party gaining 90% or 0% of the vote.
If your figures do not add up to 100% they will be rescaled automatically.
You can also input vote share movements towards or away from any party. If you enter +5, for example, the calculator will add 5% to that party's 2001 share of the vote.