“Sometimes we tell the audience that they’re all going to die and they cheer”: writer and comedian Timandra Harkness talks corpses and calculators with Iris Faraway.

Sharks, meteorites or falling out of bed: which is more likely to kill you? If anyone knows, it’s Timandra Harkness and Matt Parker, the brains behind the show ‘Your Days Are Numbered: The Maths of Death’. Performing in Bath and Bristol on 15 and 16 February, the two enthusiastically examine the hilarious and unexpected statistics behind our deaths, backed up by graphs, a Deathometer and units of so-called micromorts, each representing a one in a million chance of death. Taking a tablet of ecstasy is worth one micromort, making it as dangerous as spending six minutes in a canoe.

Maths and death make an unorthodox recipe for humour, but Harkness sees comedy as a natural reaction to such a grim topic: “There is that element of fear that makes you want to laugh at something, which I think is quite healthy.”

Death, of course, might not be the only thing the audience is afraid of. “I think people are more scared off by the maths,” she laughs. “Matt said this when we started the show together. ‘We can’t call it ‘Your Days Are Numbered: The Maths of Death’, because that word will scare people off.’ And I went, ‘What, death?’ And he went, ‘No, no, no, no, maths. Maths will scare them off.’”

Harkness and Parker met at the Cheltenham Science Festival’s FameLab, an international search to find engaging speakers on science. She judges the UK competition, while Parker, a “stand-up mathematician”, won the Audience Choice award in 2009.

“We decided we wanted to do a show together, so what are we both interested in?” Soon they discovered a shared suspicion of alarmist public health warnings. “Just this week it was all over the news that ‘Drinking two glasses of wine a day triples your risk of mouth cancer’, and we thought, ‘Triples what? What was the original risk?’ If the original risk is tiny, tripling it means it’s still tiny.”

What fates, they wondered, should we really be worrying about? Harkness and Parker began tracking death statistics through scientific papers and public records. “If you look worldwide at enough people, someone will have died of everything. But your individual chances of dying from most things are really tiny.”

While most people met fairly ordinary ends, others were more memorable: “The weirdest one was what they call ‘foreign object entering through natural orifice’. They don’t give you details, so you just think, OK, I’ll have to use my imagination…”

Overall, what they discovered was surprisingly uplifting. “When we started research, we thought it would be a really dark comedy.” Then they checked the British life expectancy rate and found it rising past the 80-year mark.

“When we did an hour-long show, we found that in that hour the average life expectancy for the UK goes up by 12 minutes. So if you’re in the audience, you feel like you’ve wasted an hour, but it’s actually only 48 minutes of your life.” The full-length show is about two hours, so the audience can look forward to a 24-minute death rebate.

Harkness and Parker happily warn the audience of their risk of dying during the show: 0.000043%. On the first night of their tour, in Salford, somebody almost contributed to their research. “Just before the interval, somebody cried from the audience, ‘Can you call an ambulance?’ And we thought it was a joke, but then we realised it wasn’t. And we thought, ‘Oh no!’” The fainting audience member recovered, but everyone was left shaken. “It was quite alarming.”

Like dying, actively participating in the maths isn’t necessary to your enjoying the show. “You don’t need to know any maths. You can bring a calculator, it’ll make Matt very excited, but you don’t need any maths at all to enjoy it,” Harkness says. “I just want people to laugh. If they go away and they think, ‘I laughed about that but I’ll never look at statistics again,’ I’m happy.”

Nevertheless, the show has attracted some specialist audience members. “When we performed in Edinburgh, someone heckled at us: ‘Which year are you taking your data from?’ I’ve had hecklers at my shows, but none of them like that!”

After shows in Bath and Bristol, Harkness and Parker are touring throughout the UK before flying to Australia to perform at the Adelaide Fringe and the Melbourne International Comedy Festival. Since most of their statistics come from UK data, new audiences mean researching new deaths: “We’re going to have to look into all the poisonous, deadly animals.”

They’re also in the early stages of researching a new show for the 2012 Edinburgh Fringe, this time focusing on engineering and technology.

However, since none of us are guaranteed to live that long, anyone interested in making the most of their remaining time on Earth may be better off attending this week’s shows. Based on audience statistics, chances of laughter are very good.

YOUR DAYS ARE NUMBERED: THE MATHS OF DEATH WAS AT THE RONDO THEATRE, ST SAVIOURS RD, BATH, BA1 6RT, WED 15 FEB, 8PM, £12/£10; AND THE COMEDY BOX AT THE HEN & CHICKEN, 210 NORTH ST, SOUTHVILLE, BRISTOL, BS3 1JF, THUR 16 FEB, 8.30PM, £12.